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
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