Answer:
{x,y} = {3/7,-43/7}
Step-by-step explanation:
System of Linear Equations entered :
[1] x + 3y = -18
[2] -x + 4y = -25
Graphic Representation of the Equations :
3y + x = -18 4y - x = -25
Solve by Substitution :
// Solve equation [1] for the variable x
[1] x = -3y - 18
// Plug this in for variable x in equation [2]
[2] -(-3y-18) + 4y = -25
[2] 7y = -43
// Solve equation [2] for the variable y
[2] 7y = - 43
[2] y = - 43/7
// By now we know this much :
x = -3y-18
y = -43/7
// Use the y value to solve for x
x = -3(-43/7)-18 = 3/7
Solution :
{x,y} = {3/7,-43/7}
Answer: 9/10 of the book.
Step-by-step explanation:
1. Convert all of the fractions to have a common denominator. 6, 5, and 3 are all multiples of 30, so we can convert the fractions to 30ths.
1/6 = 5/30
2/5 = 12/30
1/3 = 10/30
2. Add the fractions together to find the whole amount of the book Joyce has read.
5/30 + 12/30 + 10/30 = 27/30
3. Simplify
27/30 -> 9/10
Answer:
141
Step-by-step explanation:
First, you would round 72.91 to 73 because the number to the right of 7 is greater than or equal to 5, so you would round up. Same goes for 67.526. round both up to 73 and 68 then add. You would get an answer of 141 :)
Answer:
13
Step-by-step explanation:
where n is the number of terms, a1 is the first term and an is the last term. The sum of the first n terms of an arithmetic sequence is called an arithmetic series . Example 1: Find the sum of the first 20 terms of the arithmetic series if a1=5 and a20=62 .An arithmetic sequence is a sequence where the difference between any two consecutive terms is a constant. ... As with any recursive formula, the initial term of the sequence must be given. An explicit formula for an arithmetic sequence with common difference d is given by an=a1+d(n−1) a n = a 1 + d ( n − 1 ) .
A=12
120% of a =80% of b
120%a = 80%b
120a/100 = 80b/100
Divide through by 100
120a = 80b
Divide through by 80
120a/80 = b
But a=12
120x 12/80 = b
18 = b
b = 18
a+b = 12 + 18 = 30
