18. Solve for x by factoring diamond method
10x^2 - 29x - 21 = 0 becomes
(2x - 7)(5x + 3) = 0
x = 7/2, -3/5
A
19. To model this we will do
(x + 9)(x + 9) = 169
distribute
x^2 + 18x - 88 = 0
factor
(x - 4)(x + 22) = 0
The length is 4m
D
20. This can be modeled by
(l)(l +5) = 234
distribute
l^2 + 5l -234 = 0
factor
(l-13)(l+18) = 0
The length is 13
The width is 18
B
21. To find this you divide the x term by 2 and square it so
10/2 = 5
5^2
25
B
22. To find this you divide the x term by 2 and square it so
9/2 = 4.5
4.5^2
81/4
C