Question

tìm x biết 

a) -15.(x+2)+7.(2x-3)= (-50)

b)\(2.\left(x+1\right)^2=-7+15\)

Answer 1

^{a, -15×(x+2)+7×(2x-3)=-50}

-15×x+-30+14×x-21=-50

-15×x+14×x=-50+30+21

-x=1

X=-1

Answer 2

a) -15.(x+2)+7.(2x-3)= (-50)

=>-15x-30+14x-21=-50

=>(-15x+14x)-30-21=-50

=>-x-51=-50

=>-x=1

=>x=-1

b)2(x+1)²=-7+15

=>2(x+1)²=8

=>(x+1)²=4

=>x+1=2 hoặc -2

=>x=1 hoặc -3