factorise 9x²-42x+49
Answers
Answer:
(3x−7)²
Step-by-step explanation:
Factoring 9x2-42x+49
The first term is, 9x2 its coefficient is 9 .
The middle term is, -42x its coefficient is -42 .
The last term, "the constant", is +49
Step-1 : Multiply the coefficient of the first term by the constant 9 • 49 = 441
Step-2 : Find two factors of 441 whose sum equals the coefficient of the middle term, which is -42 .
-441 + -1 = -442
-147 + -3 = -150
-63 + -7 = -70
-49 + -9 = -58
-21 + -21 = -42 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -21 and -21
9x2 - 21x - 21x - 49
Step-4 : Add up the first 2 terms, pulling out like factors :
3x • (3x-7)
Add up the last 2 terms, pulling out common factors :
7 • (3x-7)
Step-5 : Add up the four terms of step 4 :
(3x-7) • (3x-7)
Which is the desired factorization.
Hope it helps!
Answer:
9x^2-42x+49
9x^2-21x-21x+49
3x(3x-7)-7(3x-7)
(3x-7)(3x-7)
i hope you understand
plz mark as brainist