math problem?

This is simply binomial factoring. Thus, we're looking


two numbers when multiplied will amt to 20 and sum to make 9.
Thus, answer is (w+5)(w+4)

(w + 5).(w + 4)
Check
w.(w + 4) + 5.(w + 4)
= w² + 4w + 5w + 20
= w² + 9w + 20

Assume x and y are the factor of w^2 + 9w +20, so w^2 + 9w + 20 = (w + x) (w + y)...(i)
(w + x) (w + y) = w^2 + wy + wx + xy
= w^2 + (x + y)w + xy
Because w^2 + (x + y)w + xy = w^2 + 9w + 20, we can find 2 equations: x + y = 9...(ii) and xy = 20...(iii)

Based on try an error on 2 equations (ii) and (iii), we found the solutions of x and y can be 4 and 5. When we submit the solutions into equation (i), then we can find w^2 + 9w + 20 = (w + x) (w + y) = (w + 4) (w + 5). Therefore, the solution should be (w + 4) (w + 5)#

Check:
(w + 4) (w + 5) = w^2 + 5w + 4w + 4*5
= w^2 + 9w + 20
Therefore, w^2 + 9w + 20 = (w + 4) (w + 5)#

w^2+9w+20
=(w+5)(w+4)#

(w + 5)(w + 4)

if it is w^2, you put w at the start of each bracket. and then find two numbers which multiply to make 20 (5 and 4), and put them also in the brackets =)

Find two numbers with SUM = 9 and PRODUCT = 20.
It is easiest to start with the PRODUCT part: 20 = 1 x 20 or 2 x 10 or 4 x 5.
Only the combination (4, 5) gives sum 9.

Conclusion:
w^2 + 9 w + 20 = (w + 4) . (w + 5)

w^2 + 9w + 20

(w + ?)(w + ?)

What two numbers multiply to make 20 and add to make 9?
The answer is +5 and +4. Therefore, this factors as

(w + 5)(w + 4)