2x^2 - 4 = 68
add 4 to both sides
2x^2 = 72
divide both sides by 2
x^2 = 36
find the square root of each sides
x = 6, -6
ANSWER: the positive value of x is 6
Answer:number of rows =10
number of places in row = 17
Step-by-step explanation:
number of rows =N
number of places in row = N+7
N(N+7)=170
N^2+7n-170=0
(N+17)(N-10)=0
N1=-17
N2=10
We can`t take negative value for quantity of smth so we throw N1 away
From that number of rows =10
number of places in row = 10+7=17
In monetary terms, you're making change. If you need more ones, you trade one 10 for 10 ones.
When I was in school, many years ago, we used small superscript-type numbers to show this:
7 3 0 ⇒ 7 2 ¹0 . . . . regrouping to gain 10 ones
7 2 ¹0 ⇒ 6 ¹2 ¹0 . . .regrouping again to gain 10 more tens
You'd have to look at the example problems that precede this page in order to see what the meaning of "magnifying glass" is.
Answer:
the number would be 11
Step-by-step explanation:
8 · x - 3 = 64
________ _ (divide both sides by 8)
8 8
x - 3 = 8
+ 3 + 3
x = 11
(check:
11 - 3 = 8
8 x 8 = 64 )
The number of possible combinations is given by
... C(18, 3) = 18!/(3!(18-3)!) = 18·17·16/(3·2·1) = 816 . . . . possible combinations
_____
There are 18 ways to choose the first one; 17 ways to choose the second one, and 16 ways to choose the 3rd one. The same 3 students can be chosen in any of 3! = 6 different orders, so the product 18·17·16 must be divided by 6 to get the number of possible combinations in which order doesn't matter.
