Question

Tìm x, biết:

\(\dfrac{x-2}{x-1}\)=\(\dfrac{x+4}{x+7}\)

Answer 1

Theo đề, ta có:

(x-2).(x+7)=(x-1).(x+4)

=x(x+7)-2(x+7)=x(x+4)-1(x+4)

=\(^{x^2}\)+7x-2x+14=\(^{x^2}\)+4x-x+4

=\(^{x^2}\)+7x-2x+\(^{x^2}\)-4x+x=14+(-4)

=2x=10

=>x=10:2=5

Answer 2

(x-2).(x+7) = (x-1).(x+4)

=> x(x+7) - 2(x+7) = x(x+4) - 1(x+4)

=> + 7x - 2x + 14 = + 4x - x+4

=> + 7x - 2x + - 4x+x = 14 + (-4)

=> 2x = 10

=> x = 10 : 2

=> x = 5