rút gọn biểu thức : n=5x−∣x∣
q=3x−4∣2x−1∣
p=∣x−1∣+2x−3
chỉ mik với
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Bài 2:
3x + 2(5 - x) = 0
<=> 3x + 10 - 2x = 0
<=> x + 10 = 0
<=> x = 0 - 10
<=> x = -10
=> x = -10
Bài 3:
6(3q + 4q) - 8(5p - q) + (p - q)
= 6.3p + 6.4q - 8.5p - (-8).q + p - q
= 18p + 24q - 40p + 8q + p - q
= (18p - 40p + p) + (24q + 8q - q)
= -21p + 31q
1) \(x\left(x+4\right)\left(x-4\right)-\left(x^2+1\right)\left(x^2-1\right)\)
\(=x\left(x^2-16\right)\)
\(=x^3-16x-\left(x^2+1\right)\left(x^2-1\right)\)
\(=x^3-16x-x^4+1\)
b) \(7x\left(4y-x\right)+4y\left(y-7x\right)-2\left(2y^2-3.5x\right)\)
\(=28xy-7x^2+4y\left(y-7x\right)-2\left(2y^2-3.5x\right)\)
\(=28xy-7x^2+4y^2-28xy-4y^2+7x\)
\(=-7x^2+7x\)
c) \(\left(3x-1\right)\left(2x-5\right)-4\left(2x^2-5x+2\right)\)
\(=6x^2-17x+5-4\left(2x^2-5x+2\right)\)
\(=6x^2-17x+5-8x^2+20x-8\)
\(=-2x^2+3x-3\)
a) x(x+4)(x-4)-(x2+1)(x2-1)
=>x(x2-42)-(x4-12)
=>x3-16x-x4+1
=>-x4-x3-15x
b) 7x(4y-x)+4y(y-7x)-2(2y2-3.5x)
=>28xy-7x2+4y2-28xy-4y2+30x
=>-7x2+30x
c) (3x+1)(2x-5)-4(2x2-5x+2)
=>6x2-15x+2x-5-8x2+20x-8
=>-2x2+7x-13
a) \(M=\left|x\right|+2x\)
\(\Rightarrow M=\left[{}\begin{matrix}x+2x=3x\left(x\ge0\right)\\-x+2x=x\left(x< 0\right)\end{matrix}\right.\)
b) \(N=5x-\left|x\right|\)
\(\Rightarrow N=\left[{}\begin{matrix}5x-x=4x\left(x\ge0\right)\\5x+x=6x\left(x< 0\right)\end{matrix}\right.\)
c) \(P=\left|x-1\right|+2x-3\)
\(\Rightarrow P=\left[{}\begin{matrix}x-1+2x-3=3x-4\left(x\ge0\right)\\1-x+2x-3=x-2\left(x< 0\right)\end{matrix}\right.\)
d) \(Q=3x-4-\left|2x-1\right|\)
\(\Rightarrow Q=\left[{}\begin{matrix}3x-4-2x+1=x-3\left(x\ge0\right)\\3x-4-1+2x=5x-5\left(x< 0\right)\end{matrix}\right.\)
\(P=x^2+8x+16+x^2-25-2x^2-2x=6x-9\\ Q=y\left(x-4\right)-5\left(x-4\right)=\left(y-5\right)\left(x-4\right)\\ Q=\left(5,5-5\right)\left(14-4\right)=0,5\cdot10=5\)
1:
a: \(\left(2x-5\right)^2-4x\left(x+3\right)\)
\(=4x^2-20x+25-4x^2-12x\)
=-32x+25
b: \(\left(x-2\right)^3-6\left(x+4\right)\left(x-4\right)-\left(x-2\right)\left(x^2+2x+4\right)\)
\(=x^3-6x^2+12x-8-\left(x^3-8\right)-6\left(x^2-16\right)\)
\(=-6x^2+12x-6x^2+96=-12x^2+12x+96\)
c: \(\left(x-1\right)^2-2\left(x-1\right)\left(x+2\right)+\left(x+2\right)^2+5\left(2x-3\right)\)
\(=\left(x-1-x-2\right)^2+5\left(2x-3\right)\)
\(=\left(-3\right)^2+5\left(2x-3\right)\)
\(=9+10x-15=10x-6\)
2:
a: \(\left(2-3x\right)^2-5x\left(x-4\right)+4\left(x-1\right)\)
\(=9x^2-12x+4-5x^2+20x+4x-4\)
\(=4x^2+12x\)
b: \(\left(3-x\right)\left(x^2+3x+9\right)+\left(x-3\right)^3\)
\(=27-x^3+x^3-9x^2+27x-27\)
\(=-9x^2+27x\)
c: \(\left(x-4\right)^2\left(x+4\right)-\left(x-4\right)\left(x+4\right)^2+3\left(x^2-16\right)\)
\(=\left(x-4\right)\left(x+4\right)\left(x-4-x-4\right)+3\left(x^2-16\right)\)
\(=\left(x^2-16\right)\left(-8\right)+3\left(x^2-16\right)\)
\(=-5\left(x^2-16\right)=-5x^2+80\)
Bài 1
A= (x-2)(2x-1)-2x(x+3)=2x2-x-4x+2-2x2-6x=-11x+2
Bài 1:
a) \(A=\left(x-2\right)\left(2x-1\right)-2x\left(x+3\right)\)
\(A=2x^2-x-4x+2-2x^2-6x\)
\(A=-11x+2\)
b) \(B=\left(3x-2\right)\left(2x+1\right)-\left(6x-1\right)\left(x+2\right)\)
\(B=6x^2+3x-4x-2-6x^2-12x+x+2\)
\(B=-12x\)
c) \(C=6x\left(2x+3\right)-\left(4x-1\right)\left(3x-2\right)\)
\(C=12x^2+18x-12x^2+8x+3x-2\)
\(C=29x-2\)
d) \(D=\left(2x+3\right)\left(5x-2\right)+\left(x+4\right)\left(2x-1\right)-6x\left(2x-3\right)\)
\(D=10x^2-4x+15x-6+2x^2-x+8x-4-12x^2+18x\)
\(D=36x-10\)
a) n=5x−∣x∣ (1)
+) Với x ≥0 <=> |x| = x
Thay vào (1) ta có :
n = 5x - x = 4x
+) Với x <0 <=> |x| = -x
Thay vào (1) ta có :
n = 5x - (-x) = 5x + x = 6x
b) q=3x−4∣2x−1∣ (2)
+) Với 2x -1 ≥0 <=> x ≥ 1/2 <=> |2x-1| = 2x-1
Thay vào (2) ta có :
q = (3x -4)(2x-1)
= 6xᒾ -8x -3x +4
= 6xᒾ -11x + 4
+) Với 2x-1<0 <=> x < 1/2 <=> |2x-1| = 1-2x
Thay vào (2) ta có :
q = (3x-4)(1-2x)
= 3x -4 -6xᒾ +8x
= -6xᒾ +11x -4
c) p=∣x−1∣+2x−3 (3)
+) Với x-1 ≥0 <=> x ≥1 <=> |x-1| = x-1
Thay vào (3) ta có :
p = x - 1 + 2x -3 = (x + 2x)+(-1-3) = 3x-4
+) Với x -1<0 <=> x<1 <=> |x-1| = 1-x
Thay vào (3) ta có :
p = 1-x + 2x -3 = (2x-x)+(1-3) = x -2
Ps : Xin lỗi vì sợ chậm trễ này nhưng thực sự tui rất bận, bro thông cảm :))
# Aeri #
∣x+\(\frac{3}{4}\)∣−\(\frac{1}{3}\)=0
nha