Answer:
x = .87, or when approximated to a fraction, 27/31
y = -3.67, or when approximated to a fraction, -1287/350
Step-by-step explanation:
Lets start by rewriting out our equations
2x + 7y = -24
18x + y = 12
Lets solve for a y value; the second equation is easiest, as the y value has no coefficient (the number that is multiplied times a variable). To do this, lets move the 18x to the other side. Now our two equations look like:
2x + 7y = -24
y = -18x + 12
Next, lets plus the second equation into the first equation in regards to y.
2x + 7(-18x + 12) = -24
Now, lets solve!
2x -126x + 84 = -24
Then, combine your terms!
-124x = -108
Divide by (-124)!
x = -108/-124
x = 27/31
Now that we know x, lets plug this back in to the first equation to find y!
2(27/31) + 7y = -24
1.74 + 7y = -24
7y = -25.74
y = -3.67, or when approximated to a fraction, -1287/350
Answer:
First number is -2.5
Second number 5
Step-by-step explanation:
Four times the first number minus three times the second number is 2.
To represent this statement, 4x -3y =2
Two times the first number increased by three times the second is 10.
To represent thsi statement, 2x+ 3y = 10
4x - 3y = 2
2x + 3y =10
4x - 2x = 2x
2x = -5
x= -2.5
The first number is -2.5
By using Substitution
2x + 3y = 10
2(-2.5) + 3y = 10
-5 + 3y = 10
3y = 10 +5
3y =15
y = 5
The second number is 5
....To check my answer
-5 + 15 = 10
I think its 1/10 miles/hour
In order to use the elimination method, we have to multiply the equation by some number, so that one of the variable has the same coefficient.
For example, multiplying the first equation by 3 and the second by 2 gives the following, equivalent system:
Now, we can subtract the two equations, and we will cancel (eliminate) the x variable:
Now that y is known, plug it into one of the equations: for example, if we use the first one we get
An easy way to solve fraction problems like this is to make each fraction have the same denominator. Since he has $100, the denominator will be 100.
2/10=?/100 10*10=100 1*10=20 20/100 of his money he wants to spend on video games
55/100 already has 100 as its denominator, so he wants to spend 55/100 on a skateboard.
3/10=?/100 10*10=100 3*10=100 30/100 is how much he wants to spend on comic books.
Add all of the fractions together to see how much he wants to spend and if he has enough.
20/100+55/100+30/100=105/100
He wants to spend $105, which is $5 more than he has.
