I need help on this math problem

Solve the systems of equations by elimination.
-2x+y=7
6x+12y=24

multiply the top equation by 3

-6x+3y=+21
6x+12y=24

add the equations
15y=45
solve for y. then put that y into either equation, and solve for x.

Can you help me with this problem.

Solve the equations by elimination
7x+3y=-1.5
2x-5y=-30.3

Multiply 1st equation by 5,

and the 2nd equation by 3.
Then add the two equations.

This will eliminate the y variable.

Take the value you get for x and substitute that value in either equation and solve for y.

helper can you show me the work because I did what you said and stll came up with the wrong answer.

Solve the systems equations by elimination.
7x+3y=-1.5
2x-5y=-30.3

5(7x + 3y = -1.5) = 35x + 15y = -7.5

3(2x - 5y = -30.3) = 6x - 15y = -90.9

35x + 15y = -7.5
6x - 15y = -90.9
Add two equations
41x + 0 = -98.4
41x = -98.4
x = -2.4

7x + 3y = -1.5
x = -2.4
7(-2.4) + 3y = -1.5
-16.8 + 3y = -1.5
3y = 15.3
y = 5.1

x = -2.4, y = 5.1

Thanks so much helped out a lot.

I got one question when both equations are subtraction do I leave them the same or switch them from subtraction to addition

You can leave the same and then subtract the equations.

I like to have one equation as addition (+)variables and one equation with negative variables. Then I can add the equation.

I know that I am less apt to make a mistake when adding equations as opposed to subtracting negative numbers.

Do what even is easiest for you.

Good luck. :)

One more problem... An orange contains 50 mg of calcium and 0.5 mg of iron. An apple contains 8 mg of calcium and 0.4 mg of iron. How many of each are required to obtain 151 mg of calcium and 2.55 mg of iron?

To solve the system of equations using the elimination method, you need to eliminate one variable by adding or subtracting the two equations.

Let's start by multiplying the first equation by 6, and the second equation by -2 to make the coefficient of x in both equations the same:

-2x + y = 7 (Equation 1)
6x + 12y = 24 (Equation 2)

Multiply Equation 1 by 6:

6(-2x + y) = 6(7)
-12x + 6y = 42 (Equation 3)

Multiply Equation 2 by -2:

-2(6x + 12y) = -2(24)
-12x - 24y = -48 (Equation 4)

Now we have eliminated the variable x, as we have the same coefficient for x in Equations 3 and 4.

Next, add Equations 3 and 4 together:

(-12x + 6y) + (-12x - 24y) = 42 - 48

Simplifying, we get:

-12x - 12x + 6y - 24y = -6

-24x - 18y = -6

Now let's solve this equation for y.

-24x - 18y = -6

Rearrange the equation:

-18y = 24x - 6

Divide both sides by -18 to solve for y:

-18y / -18 = (24x - 6) / -18

Simplifying, we get:

y = (-4/3)x + 1/3

Now that you have the value of y, you can substitute it back into either Equation 1 or Equation 2 to find x. Using Equation 1 is typically easier:

-2x + y = 7

Substitute y with (-4/3)x + 1/3:

-2x + (-4/3)x + 1/3 = 7

Multiply everything by 3 to get rid of the fractions:

-6x - 4x + 1 = 21

Combine like terms:

-10x + 1 = 21

Subtract 1 from both sides:

-10x = 20

Divide by -10 to solve for x:

x = -2

So the solution to the system of equations is x = -2 and y = (-4/3)x + 1/3.