Answer:
- The system of equations is x + y = 85 and 7/20x+2/5y=31
- To eliminate the x-variable from the equations, you can multiply the equation with the fractions by 20 and multiply the other equation by -7.
- B-She used 60 minutes for calling and 25 minutes for data.
Step-by-step explanation:
It is always a good idea to start by defining variables in such a problem. Here, we can let x represent the number of calling minutes, and y represent the number of data minutes. The the total number of minutes used is ...
x + y = 85
The total of charges is the sum of the products of charge per minute and minutes used:
7/20x + 2/5y = 31.00
We can eliminate the x-variable in these equations by multiplying the first by -7 and the second by 20, then adding the result.
-7(x +y) +20(7/20x +2/5y) = -7(85) +20(31)
-7x -7y +7x +8y = -595 +620 . . . . eliminate parentheses
y = 25 . . . . . . . . simplify
Then the value of x is
x = 85 -y = 85 -25
x = 60
3000+200+60+4 I think would be the answer from what I remember
Answer:
Yes it is!
Step-by-step explanation:
If you want to know whether it is, use the pytheoream theory. a2+b2=c2
a is the shortest side, b is the second longest and c is the longest.
In this case, the equation will be:
8 sq + 15 sq = 17 sq
64 + 225 = 289
= It is a right-angled triangle!
Answer: 20 hours
Step-by-step explanation:
Equation: 15x = 300
Isolate the variable.
Divide both sides by 15: ¹⁵ˣ⁄₁₅ = ³⁰⁰⁄₁₅
x = 20
Ivan needs to work 20 hours in order to afford the bicycle.
