The school can buy fifteen notebooks and nineteen tablets. 15X7=105 and 5X19=95. 95+105=200. The first thing you want to do is realize that 5Xanything will give you an answer that has a 0 or a five at the end, so you want to find a product by 7 that ends with a 0 or 5 too.
Answer:
The value of x is, 
Explanation:
Given: 
Distributive Property states that when a number is multiplied by the sum of two numbers, the first number can be distributed to both of those numbers and multiplied by each of them separately.
If 
Now, using distributive property on left hand side of the given expression as:
or 
Addition Property of equality state that we add the same number from both sides of an equation.
Add r to both sides of an equation:

Simplify:

Subtraction Property of equality state that we subtract the same number from both sides of an equation.
Subtract Nx from both sides of an equation;

Simplify:
or

Division Property of equality states that we divide the same number from both sides of an equation.
Divide by (34-N) to both sides of an equation;

On Simplify:

Change in number of seats = 144 - 111 = 33
percentage increase = 33/111 x 100 = 29.8% (nearest tenths)
That is when h=0
so assuming yo meant
h(t)=-16t²+24t+16
solve for t such that h(t)=0
because when height=0, the gymnast hits the ground
so
0=-16t²+24t+16
using math (imma complete the square
0=-16(t²-3/2t)+16
0=-16(t²-3/2t+9/16-9/16)+16
0=-16((t-3/4)²-9/16)+16
0=-16(t-3/4)²+9+16
0=-16(t-3/4)²+25
-25=-16(t-3/4)²
25/16=(t-3/4)²
sqrt both sides
+/-5/4=t-3/4
3/4+/-5/4=t
if we do plus (because minus would give us negative height)
8/4=t
2=t
it takes 2 seconds