factorise 12r²+25r+12=0
Answers
Answer:
Factoring 12r2-25r+12
The first term is, 12r2 its coefficient is 12 .
The middle term is, -25r its coefficient is -25 .
The last term, "the constant", is +12
Step-1 : Multiply the coefficient of the first term by the constant 12 • 12 = 144
Step-2 : Find two factors of 144 whose sum equals the coefficient of the middle term, which is -25 .
-144 + -1 = -145
-72 + -2 = -74
-48 + -3 = -51
-36 + -4 = -40
-24 + -6 = -30
-18 + -8 = -26
-16 + -9 = -25 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -16 and -9
12r2 - 16r - 9r - 12
Step-4 : Add up the first 2 terms, pulling out like factors :
4r • (3r-4)
Add up the last 2 terms, pulling out common factors :
3 • (3r-4)
Step-5 : Add up the four terms of step 4 :
(4r-3) • (3r-4)
Which is the desired factorization