Question

$\text{Find the value for x, y for : x+3y=15, 2x-5y+10=0}$

• A. 45/11, 40/11
• B. 40/11, 45/11
• C. 23/17, 20/17
• D. None of these

Answer 1

The correct option is A

45/11, 40/11

x+3y=15, ................(i)

2x-5y+10=0 .............(ii)

From equation (i) x=15-3y

By substituting the value of x in equation (ii) we get

2x-5y=-10

$\Rightarrow 2(15-3y)-5y=-10\Rightarrow 30-6y-5y=-10\Rightarrow -11y=-40\Rightarrow y=\frac{40}{11}$

Substituting the value of y in equation (i) we get

$x=15-3\left(\frac{40}{11}\right)\Rightarrow x=15-\frac{120}{11}\Rightarrow x=\frac{165-120}{11}=\frac{45}{11}\therefore x=\frac{45}{11},y=\frac{40}{11}$​