solve each equation by factoring K^+15K=-56
Answers
Answer:
"k2" was replaced by "k^2".
k^2+15*k-(-56)=0
Step-by-step explanation:
Factoring k2+15k+56
The first term is, k2 its coefficient is 1 .
The middle term is, +15k its coefficient is 15 .
The last term, "the constant", is +56
Step-1 : Multiply the coefficient of the first term by the constant 1 • 56 = 56
Step-2 : Find two factors of 56 whose sum equals the coefficient of the middle term, which is 15 .
-56 + -1 = -57
-28 + -2 = -30
-14 + -4 = -18
-8 + -7 = -15
-7 + -8 = -15
-4 + -14 = -18
-2 + -28 = -30
-1 + -56 = -57
1 + 56 = 57
2 + 28 = 30
4 + 14 = 18
7 + 8 = 15 That's it
Step-3 : Rewrite the polynomial splitting the middle term using the two factors found in step 2 above, 7 and 8
k2 + 7k + 8k + 56
Step-4 : Add up the first 2 terms, pulling out like factors :
k • (k+7)
Add up the last 2 terms, pulling out common factors :
8 • (k+7)
Step-5 : Add up the four terms of step 4 :
(k+8) • (k+7)
(k + 8) • (k + 7) = 0
Solve : k+8 = 0
Subtract 8 from both sides of the equation :
k = -8
Solve : k+7 = 0
Subtract 7 from both sides of the equation : k = -7
Answer:
Step-by-step explanation:
k^+15k+56=0
8*7=56
8+7=15
therefore
(k+8)(k+7)