Answer:
I think a is correct answer.
53 + 9x < 115
THE LESS THAN SYMBOL SHOULD HAVE A LINE UNDER IT!
Answer:
Given the system of equation:
......[1]
......[2]
we can rewrite equation [2] as;
......[3]
Substitute equation [3] into [1] to eliminate x, and solve for y;

Using distributive property: 

Combine like terms;
16 - 8y = -4
Add 4 to both sides we have;
20 - 8y = 0
Add 8y to both sides we have;
20 = 8y
Divide 8 to both sides we have;

Substitute the y-value in [3] we have;

x = 8 - 5 = 3
Therefore, the expression should be substituted into the first equation is,
and also the value of x = 3 and y = 2.5
Remmeber, you can do anything to an equation as long as you do it to both sides
for inequalities, if you multiply or divide both sides by a negive, flip the direction of the inequality sign
pemdas always applies
but also the commutative property and assiociative property
so
2(5y+13)-6<20
add 6 both sides
2(5y+13)<26
divide both sides by 2 (easier that distributing)
5y+13<13
minus 13 both sides
5y<0
y<0 is the solution
Answer:
because the length is 4 feet more than the width
=> the length is x + 4 (feet)
because the base has an area of 21 square feet
=> x(x + 4) = 21
<=> x² + 4x = 21