4:5 = x : 15
let x be blue marbles
4(15) = 5x
x = 12
therefore 12 blue marbles
Hello,
To solve this system of equations, we want to add or subtract the equations so that either x or y cancels out.
We can multiply the first equation by -2, so that 5y will become -10y, and then add the equation with the second so -10y and 10y will cancel out.
Multiplying the first equation by -2, we get:
-4x - 10y = -30
Add this to the second equation and we get:
x = 5
So, we have x = 5. However, we should plug it into both equations to solve for y and make sure both answers check out.
Doing this for the first equation, we have:
2(5) + 5y = 15
10 + 5y = 15
Subtract 10 from both sides to get:
5y = 5
Divide by 5 on both sides to get:
y = 1
We will now see if x = 5 and y = 1 works for the second equation.
5x + 10y = 35
5(5) + 10(1) = 35
35 = 35, checks out
So, x = 5 and y = 1.
Option choice B is correct.
Hope this helps!
Find the amount of water in liter for a year
3,000 gallons = 3,000 × 3.8 liters
3,000 gallons = 11,400 liters
There are 11,400 liters of water for a year
Find the amount of water in liter for a month
11,400 liters/12 months = 950 liters/month
There are 950 liters of water in a month
Lunch
Step-by-step explanation:
she eats 900 cals at lunch, but at dinner she has 800 and breakfast she has 600. 900 is the most cals so lunch is the meal with the most calories.
