Answer:(9y-7)(9y+7)
Step-by-step explanation:
81y^2-49
=(9y)^2-(7)^2
=(9y-7)(9y+7)
Answer:
Step-by-step explanation:
The answer is 10.0
Answer:
The area of the trapezium is 
Step-by-step explanation:
Area of a trapezium:

This formula is valid if b1 and b2 are parallel and h is perpendicular to both.
Since the trapezium given in the problem satisfies those conditions, we use the formula with:
b1=15 cm
b2=7 cm
h=6.8 cm


The area of the trapezium is 
Answer:
Therefore first number is 3 and second number is 18
Step-by-step explanation:
Sum of the two numbers is 21 and Second number is six times the first number
x+6x = 21
7x = 21
x = 21/7
x = 3
substitute x value in 6x to find second number,
= 6x
= 6*3
= 18
Her answer is wrong because the product of 78.112 = 8736.