Answer:
10 weeks
Step-by-step explanation:
Let's set an equation for you and your brother.
You have $90 plus $18 for every week you save (x).
90+18x
And your brother has $120 plus $15 dollars per week that he saves (x)
120+15x
You want to have the sum of the money equal so combine the two concluded statements
90+18x=120+15x
Arrange them so that you have like terms on each side
90+18x-15x=12+15x-15x
90+3x=120
90-90+3x=120-90
3x=30
x=10
"x" is our number of weeks you and your brother save so the answer is 10 weeks
Just to be sure you can use our equation and plug 10 for every time you see x to make sure our answer is right.
In word form: Sixty four
in expanded form: 6x10 + 4x1
in place value form: 6 tens + 4 ones
in Roman numeral form: LXIV
in Arabic numeral form: ٦٤
Answer:
97.5
Step-by-step explanation:
3.5cm cube surface area:
3.5*3.5*6 (the 6 faces of the cube) =
73.5
2cm cube surface area:
2*2*6 =
24
combined surface area:
73.5+24=
97.5

The rows add up to

, respectively. (Notice they're all powers of 2)
The sum of the numbers in row

is

.
The last problem can be solved with the binomial theorem, but I'll assume you don't take that for granted. You can prove this claim by induction. When

,

so the base case holds. Assume the claim holds for

, so that

Use this to show that it holds for

.



Notice that






So you can write the expansion for

as

and since

, you have

and so the claim holds for

, thus proving the claim overall that

Setting

gives

which agrees with the result obtained for part (c).
Answer:
-15x^2 +8x -1
Step-by-step explanation:
(3x – 1)(-5x + 1)=
3x(-5x) + 3x(1) - 1(-5x) -1 =
-15x^2 +3x +5x -1 =
-15x^2 +8x -1
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