77(7) = 539, the total points of all her tests
539 - 18 + 81 = correct total points = 602
602/7 = 86 which is the new average
Answer:
x = 14
2x = 28
6x = 84
Step-by-step explanation:
6x = 180 - 124 + 2x
4x = 56
x = 14
The substitution property of equality, one of the eight properties of equality, states that if x = y, then x can be substituted in for y in any equation, and y can be substituted for x in any equation.
We are given that Kristine spends $20 and saves the rest each time she get paid.
We can use slope-intercept form y=mx+b to represent the equation.
Where x represents the amount Kristine earns and y represents the amount she saves.
Kristine spends $20. Therefore b= -20.
Plugging mx as just x and b=-20.
<h3>y = x-20.</h3><h3>If we plug y=0, we get </h3><h3>0 = x-20</h3><h3>x=20.</h3><h3>We can see in 4th option we have x-intercept =20.</h3><h3>Therefore, correct option is 4th option. </h3><h3 />