Question

The area of a rectangle is given by A = x2 – 2x + 30. Find the value of x if the total area of the rectangle is equal to 45 square units

Answer 1

is the equation \[x^2-2x+30\] or \[x2-2x+30\]

Answer 2

the first one

Answer 3

okay then this problem would be solved by factoring

Answer 4

are you familiar with how to factor an equation?

Answer 5

not really

Answer 6

okay i will try my best to explain

Answer 7

the equation will be split into two brackets like this (x+y) (x+y). And the two brackets when multiplied should equal your original equation which in this case would be x^2+2xy+y^2.

Answer 8

okay so what happens to the 45

Answer 9

so your equation is x^2-2x+30=45. the first step would be to determine the first number in each of your brackets, which corresponds to the first number in your equation x^2.
and the inside factors correspond to the inner and last numbers which are -2x and -15. your final factor should come to be (x-5) (x+3)

Answer 10

so do you set both equations to zero

Answer 11

Then you solve each of the factors for the x so the first factor would give you x=5 and the second factor would give you x=-3. So you test these answers with your original equation.

Answer 12

okay thank you

Answer 13

no problem