Question

find the product of (y+4)(y+7)​

Answer 1

Answer:

y²+11y+28

Step-by-step explanation:

y²+7y+4y+28

y²+11y+28

Answer 2

We have , (y+4)(y+7) to solve !! Rather than following the traditional multiplication method we can solve the sum in a very easy way using algebraic identities .

When observed , the given question is in the form of ( x + a ) ( x + b ) = x² + ab + (a+b)x !!

Here ,

• x = y
• a = 4
• b = 7

Now , Substitute the values as stated !!

$\implies\tt{(y + 4)(y + 7)} \\ \implies \tt{ {y}^{2} + 7 \times 4 + (7 + 4)y} \\ \implies \tt{ {y}^{2} + 11y + 28}$

You can even check the answer by the normal multiplication method :

$\implies \tt{(y + 4)(y + 7)} \\ \implies \tt{y(y + 7) + 4(y + 7)} \\ \implies \tt{ {y}^{2} + 7y + 4y + 28} \\ \implies \tt{ {y}^{2} + 11y + 28}$

Hence , in both the methods the answer is same !! It depends upon you which one you would choose !!

Have fun with Math !!