91.4 * 100 = 9140
68.5 * 100 = 6850
9140 * 6850 = 62609000cm²
Answer:
The phones of the first group have is 11
The ipads the first group has is 6
Step-by-step explanation:
Assuming the number of phones the first group has is x while the number of the ipads the first group has is y.
x+y=17;2x+3y=40.
x+y=17
x+y+−y=17+−y(Add -y to both sides)
x=−y+17
2x+3y=40
2(−y+17)+3y=40
y+34=40(Simplify both sides of the equation)
y+34+−34=40+−34(Add -34 to both sides)
y=6
x=−y+17
x=−6+17
x=11(Simplify both sides of the equation)
x=11 and y=6
So the number of phones the first group have is 11 and the number of ipads the first group have is 6
So you would add 12 to the other side of the equation, and 9+12=21, so x=21.
The big keyword here is the word RATIO. Ratio of what? The ratio of girls to boys in the entire grade. A ratio is just the two amounts divided by each other (you can also call it the slope, but ignore that if that makes it more confusing).
(81 girls)/(72 boys)
Simplify it by breaking it up a bit.
81 = 9 * 9
72 = 9 * 8

Cross out similar terms to gain the result of:

What they want from us is the ratio of girls if a group has 16 boys. So set it up like this:

Just by looking at this you may be able to solve for "x" if you have a good understanding of fractions, but instead let's do the long way.
First off is to get "x" alone by multiplying 16 boys on both sides.
x =

Remember that:
16 = 8*2
x =

Cancel out the like terms (8) to give you:
x = 18 girls
∠AB = (2x + 1)°
∠BC = (3x - 4)°
∠AC = 62°
∠AB + ∠BC = ∠AC
(2x + 1)° + (3x - 4)° = 62°
(2x + 1) + (3x - 4) = 62
2x + 3x + 1 - 4 = 62
5x - 3 = 62
+ 3 + 3
5x = 65
5 5
x = 13°
Line B is a bisector between ∠AC.