Question

The product of two numbers is 713. The first number is 9 more than the second number. Which equation can be used to

find x, the greater number?
Ox(x - 9) = 713
O x(x + 9) = 713
O x - 9 = 713
O x2 + 9 = 713

Answer 1

Answer: x(x - 9) = 713

Explanation:

Let the first number be x and the second number be y.

From the first statement;

xy = 713 ............. equation 1

From the second statement , the first number is 9 more than the second number , this means that x is greater than y by 9 , in equation form , we have

x - y = 9 ............ equation 2

Combining the two equations , we have

xy = 713 ........... equation 1

x - y = 9 .......... equation 2

From equation 2 , make y the subject of the formula , that is

y = x - 9 ............ equation 3

substitute equation 3 into equation 1 , we have

x ( x - 9 ) = 713

which will result in a quadratic equation

`x^(2)` - 9x = 713

`x^(2)` - 9x - 713 = 0