Đáp án:
Giải thích các bước giải:
a) 4(𝑥+3)(3𝑥−2)−3(𝑥−1)(4𝑥−1)=−27
=>4𝑥(3𝑥−2)+12(3𝑥−2)−3(𝑥−1)(4𝑥−1)=−27
=>12𝑥^2−8𝑥+12(3𝑥−2)−3(𝑥−1)(4𝑥−1)=−27
=>12𝑥^2−8𝑥+36𝑥−24−3(𝑥−1)(4𝑥−1)=−27
=>12𝑥^2+28𝑥−24−3(𝑥−1)(4𝑥−1)=−27
=>12𝑥^2+28𝑥−24−3𝑥(4𝑥−1)+3(4𝑥−1)=−27
=>12𝑥^2+28𝑥−24−12𝑥2+3𝑥+3(4𝑥−1)=−27
=>12𝑥^2+28𝑥−24−12𝑥2+3𝑥+12𝑥−3=−27
=>12𝑥^2+28𝑥−24−12𝑥2+15𝑥−3=−27
=>12𝑥^2+28𝑥−27−12𝑥2+15𝑥=−27
=>28𝑥−27+15𝑥=−27
=>43𝑥−27=−27
=>43𝑥=0
=>𝑥=0
b)5𝑥(12𝑥+7)−3𝑥(20𝑥−5)=−100
=>60𝑥2+35𝑥−3𝑥(20𝑥−5)=−100
=>60𝑥2+35𝑥−60𝑥2+15𝑥=−100
=>35𝑥+15𝑥=−100
=>50𝑥=−100
=>x=−100/50
=>𝑥=−2
c)0,6x(x - 0,5) - 0,3x(2x - 1,3) = 0,138
<=>0,6x^2-0,3-0,6x^2+0,39x=0,138
<=>-0,3+0,39x=0,138
<=>0,39x=0,438
<=>x=73/65≈1,12
Giải thích các bước giải:
