8. Factor 5t² - t -18
9. Factor 25x² - 9
10. Factor 9t² + 12t + 4
3 answers
See https://www.jiskha.com/display.cgi?id=1522693893#1522693893.1522695283
Factoring takes some practice.
(5t-?)(t+?)
or (5x+?)(t-?) so just play around and you will finally wind up with
10-9=1, so
(5t+9)(t-2) = 5t^2+9t-10t-18 = 5t^2-t-18
also, recall that (a-b)(a+b) = a^2-b^2
25x^2-9 = (5x)^2 - 3^2
(5t-?)(t+?)
or (5x+?)(t-?) so just play around and you will finally wind up with
10-9=1, so
(5t+9)(t-2) = 5t^2+9t-10t-18 = 5t^2-t-18
also, recall that (a-b)(a+b) = a^2-b^2
25x^2-9 = (5x)^2 - 3^2
10. remember 3*2 = 6
6+6 = 12
6+6 = 12