Hope this helps you out :D
It’s 2 equations so in order to solve the previous system, you can use different methods, as for example substitution or addition of equations. In this case, you use the second one, due to the fact you have 7x in one equation and -7x in the other equation. In this way you can easily eliminate variable x and then solve for y. With the value of y you can replace in any of the two equations and solve for x.
7x-y=-1
-7x+3y=-25
Summarizing, you proceed as follow:
- add up the given equations
7x - y = -1
-7x+3y=-25
——————
0 +2y=-26
- solve for y in the previous equation
2y=-26
y=-26/2
y=-13
- replace the obtained value of y in one of the given equations, and solve for x
7x-(-13)=-1
7x+13=-1
7x=-1-13
7x=-14
x=-14
x=-14/7
x=-2
Hence, the solution of the given systems of equation is:
X=-2
Y=-13
Answer:
there was 3 pounds of raisins and 4 pounds peanuts.
Step-by-step explanation:
4 times 3 =12 and 2 times 4 = 8. 3+4=7 so 7 pounds. 12+8=20 so $20.
Answer:
Step-by-step explanation:
3x + 3
6 + 2x
3x + 2x = 5x
3 + 6 = 9
5x + 9
Answer:
x + (5x-9)
Step-by-step explanation:
x stands for the number of coins Nancy has
Kevin has 9 less than 5 times what Nancy has, so his part of the expression is 5x-9
To find the total number of coins they have, you have to add Nancy's number of coins x plus Kevin's number of coins 5x-9
x + (5x-9)
But you have to put parentheses around Kevin's 5x-9 so that part of the expression is calculated first, as per order of operations
Answer: x = 13/5
Explanation:
(x+4)/(3x+1) = 3/4
Cross multiply:
4(x+4) = 3(3x+1)
4x + 16 = 9x + 3
4x - 9x = 3 - 16
-5x = -13
x = -13/-5
x = 13/5
