if r(x)=4x^2-3x+7, find r(3a^2)?

0 ⤊

a. 36a^4 -9a^2+7
b. 144a^4 -9a^2+7
c. 36a^4+9a^2+7
d. 12a^4 -9a^2+7

2007-01-28 02:06:43 · 3 answers · asked by lana l 1 in Science & Mathematics ➔ Mathematics

r(3a^2) = 4(3a^2)^2 - 3(3a^2) + 7
= 4(9a^4) - 9a^2 + 7
= 36a^4 - 9a^2 + 7

answer is a

2007-01-28 02:12:13 · answer #1 · answered by Anonymous · 0⤊ 0⤋

r(x) = 4x^2 - 3x + 7

r(3a^2) = 4[3a^2]^2 - 3[3a^2] + 7

= 4[9a^4] - 9a^2 + 7
= 36a^4 - 9a^2 + 7

2007-01-28 10:09:59 · answer #2 · answered by Puggy 7 · 0⤊ 0⤋

a.36a^4-9a^2+7

2007-01-28 10:18:16 · answer #3 · answered by raj 7 · 0⤊ 0⤋