Question

Please help math

The solutions to 15(2a – 2) = 5(a2 – 1) are:

a = 1, a = –1

a = 5, a = –1

a = 5, a = 1

Answer 1

c

Explanation:

i took the test

Answer 2

`\displaystyle\\ 15(2a - 2) = 5(a^2 -1) \\ \\ 30a - 30 = 5a^2-5\\\\ -5a^2 + 30a -30 + 5 =0\\\\ -5a^2 + 30a -25 =0 ~~~~~\Big| * (-1) \\\\ 5a^2 - 30a +25 = 0~~~~~\Big| : 5 \\\\ a^2 - 6a +5 = 0 \\ \\ a_(12)= (-b\pm √(b^2-4ac))/(2a)= (6\pm √(36-20))/(2)= (6\pm √(16))/(2)=(6\pm 4)/(2)= \boxed{3\pm 2} \\ \\ a_1 = 3+ 2 = \boxed{5}\\\\ a_2 = 3-2 = \boxed{1}`