Question 831590
p=40+q and 7p=-9q+360

so we will times p=40+q by 7,
7p=280+7q

now we have
7p=280+7q
7p=360-9q

we will minus the first equation from the second
we are left with
0=80-16q
16q=80
q=5

put q is 5 into 7p=280+7q to find p
7p = 280 + 35
p=315/7

p=45 and q=5