Question

The product of 7 and the sum of a
number and 4 is 70. What is the number?

Answer 1

x+ y = -7, or

y = -x-7 …(1)

xy = -60, or

y = -60/x …(2)

Equate (1) and (2)

-x-7 = -60/x, or

x+7 = 60/x, or

x^2+7x-60=0

(x+12)(x-5) = 0

x = -12 or +5 and y = +5 or -12, respectively.