Question

Daca 1 supra 3 = b supra 5, determinati x  din propozitia x(10a-4b) supra 5a + b = 7 supra 2

Answer 1

$\frac{1}{3}$=$\frac{b}{5}$  ⇒ b=5/3
2x(10a-4b)= 7(5a+b) ⇒ x=7(5a+b)/2(10a-4b)
5a+b=5a+5/3=15a+5/3
10a-4b=10a-4*5/3=30a-20/3
x=7*(15a+5)/3 *1*3/2(30a-20)
x=7(15a+5)/2(30a-20)