Answer:
Solution: x = 2, y = -1 or (2, -1)
Step-by-step explanation:
Equation 1: 2x + y = 3
Equation 2: 5x - 2y = 12
Using the substitution method:
Transform the Equation 1 into its slope-intercept form:
2x + y = 3
2x - 2x + y = -2x + 3
y = 2x + 3
Substitute the value of y = -2x + 3 into Equation 2:
5x - 2y = 12
5x - 2(-2x + 3) = 12
5x + 4x - 6 = 12
9x - 6 = 12
9x - 6 + 6 = 12 + 6
9x = 18
9x/9 = 18/9
x = 2
Substitute the value of x = 2 into Equation 2 to solve for y:
5x - 2y = 12
5(2) - 2y = 12
10 - 2y = 12
10 - 10 - 2y = 12 - 10
-2y = 2
-2y/-2 = 2/-2
y = -1
Double-check whether the values for x and y will provide a true statement for both equations:
Equation 1: 2x + y = 3
2(2) + (-1) = 3
4 - 1 = 3
3 = 3 (True statement)
Equation 2: 5x - 2y = 12
5(2) - 2(-1) = 12
10 + 2 = 12
12 = 12 (True statement)
Therefore, the correct answers are: x = 2; y = -1 or (2, -1).
Answer:
33
Step-by-step explanation:
first you set up the problem, supplementary angles equal 180 degrees so the equation should look like, 4x+x+15=180. then you solve from there by combining like terms and you should get x equal to 33
Answer:
60 km/h
Step-by-step explanation:
Let us use the x to represent the speed of the car since it is the smaller value.
Then, the distance covered by the car is 4x since was going 4 kph.
The distance covered by the train is (x+5) times 7 or 7x+35.
We know that the total distance covered is 640 km.
Using this information, we can set up the equation 4x+7x+35=640.
By subtracting both sides by 35 and combining the x's, we get a new equation of 11x=605.
After this, we divide both sides by 11 and get x=55.
Lastly, we add 5 to 55 since the train is 5 km faster than the car and that x stood for the car.
Train=60 km/h
Answer:
12
Step-by-step explanation:
This can be solved by working backwards.
7 is one more than half the number of invitations.
Subtract 1. 6 is half the number of invitations.
Double.
12 is the full number of invitations.
Algebra (if you must!):
x = number of invitations
x/2 + 1 = 7
Subtract 1.
x/2 = 6
Multiply by 2.
x = 12
Answer:
1.58
Step-by-step explanation:
15.8 x 0.1= 1.58
