Question

7x+5y=11 3x+y=7 solve for xy

Answer 1

are you asking to solve for x*y or for the variables x and y

Answer 2

to solve for the variables x and y, first you should choose to either solve this via substitution or elimination

Answer 3

in this case, substitution will be easier.
Original equations:
7x+5y=11
3x+y=7
first manipulate one so that you have solved for y:
3x-3x+y=7-3x
y=-3x+7
then substitute in for y in the other equation (7x+5y=11)
7x+5(-3x+7)=11
7x-15x+35=11
-35 -35
-8x=-24
/-8 /-8
x=3
then plug your x value into one of the original equations and solve for y:
7(3)+5y=11
21+5y=11
5y=-10
y=-2

Answer 4

of course you'll also want to double check answers by plugging them in

Answer 5

7x+5y=11
3x+y=7 y = 7-3x I'm using substitution

7x + 5(7-3x)=11
7x + 35-15x = 11
-8x + 35 = 11
-8x = -24
x = 3

So...
7(3)+5y=11
21 + 5y = 11
5y = 11-21
5y = -10
y = -2

solution is (3,-2) no check solution in 2nd equation: 3x+y=7
3(3)+-2 = 7
9+-2=7
7=7 it works