Answer:
2n +10= 140
4n- 40= 80
2n= 3n - 20
Step-by-step explanation:
it is the am progression or sum progression
2. y=2x+3
When x =0 and y= something, the 'something' is your y-intercept which is b in the y=mx+b formula. Then we look at what is changed in the x and y value to determine the m part. the x increase by 1 and y increase by 2 so the m part is 2.
3. y=-7x
Same as the last one, there is no y-inter this time because the y=0 when x=0/ So the y deceased by 7 each time and x incease by 1 so it is -7 for the m part.
Answer:
(x, y) = (-4, 15)
Step-by-step explanation:
The two equations have the same coefficient for y, so you can eliminate y by subtracting one equation from the other. Here the x coefficient is largest for the first equation, so it will work best to subtract the second equation.
(3x +y) -(2x +y) = (3) -(7)
x = -4 . . . . . . . . simplify
Now, we can find y by substituting this value for x.
2(-4) +y = 7
y = 7 +8 = 15 . . . . . add 8 to both sides of the equation
The solution is (x, y) = (-4, 15).
81.
Add them all and then divide by the number of days (by 5)