Answer: x = 7 or x = -8
x² + x - 56 = 0
⇔ x² + 8x - 7x - 56 = 0
⇔ x(x + 8) - 7(x + 8) = 0
⇔ (x - 7)(x + 8) = 0
⇔ x - 7 = 0
or x + 8 = 0
⇔ x = 7 or x = -8
Step-by-step explanation:
Answer:
True!
Step-by-step explanation:
Distributive property
C. 51* I am pretty sure is it
x + y = 24 where x and y are the 2 parts of diagonal Other diagonal wil be smaller that 24.
x^2 + z^2 = 13^2
y^2 + z^2 = 20^2 where z = 0.5 * length of smaller diagonal)
form last 2 equations
y^2 - x^2 = 20^2 - 13^2 = 231
now y = 24-x so we have
(24 - x)^2 - x^2 = 231
576 - 48x = 231
48x = 345
x = 7.1875
z^2 = 13^2 - 7.1875^2 = 117.34
z = 1.83
so smaller diagonal = 21.66 cm
looks like its the third choice.