Question

Is (7, 2) a solution to this system of equations?

16x + 8y = 11
x + y = 9

Answer 1

Explanation:

16x+8y=11

x+y=9

Make x subject of formula, then x=9-y

Substitute x into equation 1

16(9-y)+8y=11

144-16y+8y=11

-8y=11-144

-8y=-133

Then, y=-133/-8

y=16.625

Also x=9-y

Then, x=9-16.625

y=-7.625

Then, the solution (7,2) is not a solution to the simultaneous equation, it is only sufficient for equation 2, it doesn't satisfy equation 1

Them the solution to the simultaneous equation is (x, y)=(16.625,-7.625)