factorise the following expression 7a^2-19-6
Answers
Answer:
7a - 2) • (a + 3)
Step-by-step explanation:
Step by Step Solution:
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Reformatting the input :
Changes made to your input should not affect the solution:
(1): "a2" was replaced by "a^2".
STEP
1
:
Equation at the end of step 1
(7a2 + 19a) - 6
STEP
2
:
Trying to factor by splitting the middle term
2.1 Factoring 7a2+19a-6
The first term is, 7a2 its coefficient is 7 .
The middle term is, +19a its coefficient is 19 .
The last term, "the constant", is -6
Step-1 : Multiply the coefficient of the first term by the constant 7 • -6 = -42
Step-2 : Find two factors of -42 whose sum equals the coefficient of the middle term, which is 19 .
-42 + 1 = -41
-21 + 2 = -19
-14 + 3 = -11
-7 + 6 = -1
-6 + 7 = 1
-3 + 14 = 11
-2 + 21 = 19 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, -2 and 21
7a2 - 2a + 21a - 6
Step-4 : Add up the first 2 terms, pulling out like factors :
a • (7a-2)
Add up the last 2 terms, pulling out common factors :
3 • (7a-2)
Step-5 : Add up the four terms of step 4 :
(a+3) • (7a-2)
Which is the desired factorization
Final result :
(7a - 2) • (a + 3)