Simple 8th grade math, picture below.

Its d

Step-by-step explanation:

10-7 is 3, -15+ 8 is -7. Making it 3/4 - (-7/6) so you have to find a common denominator. The common D is 12 but you have to multiply the numerator as well as the denominator to make it true. 4*3 and 3*3, = 9/12. 6*2 and -7*2,= -14/12. Then u subtract numerators and denominators. 9- (-14) which is the same as 9 + 14 = 23. And the 12 stays the same. Now you have 23/12 so then you simplify it to 1 11/12.  Check your work by adding 12 and 11 to get 23/12.

i leave the calculator work to you.

7. diameter 4 miles, circumference 4π miles

8. radius 0.2 miles, circumference 0.4π miles

[this is a bad problem because the actual radius of a car on the track is less than 0.2 miles so the answer is less than 0.4π miles]

9. radius 6 feet, circumference 12π feet

10. diameter 14 cm, circumference 14π cm

11. diameter 4.8 feet, circumference 4.8π feet

infinitely many solutions

step-by-step explanation:

we have been given the equation;

2(2x + 3) = -4 + 2(2x + 5)

we need to determine the value of x.

2(2x + 3), we expand this expression to obtain 4x + 6

similarly 2(2x + 5) will become 4x + 10

now we have;

4x + 6 = -4 + 4x + 10

4x + 6 = 4x + 10 - 4

4x + 6 = 4x + 6

the expression on the left hand side is identical to the one on the right hand side. therefore, we are looking at just a single straight line whose equation is;

y = 4x + 6

consequently, we shall have infinitely many solutions