Question

Simplify the expression, then evaluate when x=5 and y=6. x(y+4)+3(2x+7y)

Answer 1

Answer:

Simplification

x(y+4)+3(2x+7y) = xy + 10x + 21y

= x(y + 10) + 21y

On evaluation when x=5 and y=6,

The expression is equal to 206

Step-by-step explanation:

Note that x and y are unknown variables.

On expansion,

x(y+4)+3(2x+7y)

= xXy + xX4 + 3X2x + 3X7y

= xy + 4x + 6x + 21y

= xy + 10x + 21y

On factorising,

xy + 10x + 21y = x(y + 10) + 21y

Evaluation when x=5 and y = 6

We substitute the given values of x and y into the simplified expression

xy + 10x + 21y

= 5X6 + 10X5 + 21X6

= 30 + 50 + 126

= 206

Therefore, on evaluation of the given expression, when x=5 and y=6, we get 206