You can write the dimensions of the rectangle as (x + 2) and (x - 5), and because the area is base × height, you can multiply the brackets together and make it equal to 56:
(x + 2)(2x - 5) = 56
2x² + 4x - 5x - 10 = 56
x² - x - 10 = 56
Now because you have an x², you need to make the equation equal to 0 so you can factorise, so:
2x² - x - 10 = 56
- 56
2x² - x - 66 = 0
(x - 6)(2x + 11)
So x is 6, because the other option is -5.5 and you cannot have a negative length.
I hope this helps!
Answer:
x plus 2 equals three x minus eight.
Answer:
x^2 - 6x + 9
Step-by-step explanation:
(x-3)^2
(x-3)(x-3)
x^2 -3x -3x + 9
x^2 - 6x + 9
^2 means (x - 3) times itself twice.
(x - 3)(x - 3) multiplying polynomials- Firsts, Outs, Inners, Lasts (FOIL)
Firsts (x* x) Outs (x*-3) Inners (-3 * x) Lasts (-3*-3)
xx -3x -3x +9 Combine like terms.
-3x -3x Adding/subtracting integers- same signs means you add
and keep the sign.
x^2 -6x + 9
Equation B.
The average of the sum of the existing 3 scores plus the score of the new test should equal 85.
To solve this, multiply both sides by 4 and subtract 256. The student needs an 84 in order to have an average of 85.
