Solve Each Sysem Using Substitution. Check ach solution.

a = 2/5b -3
a = 2b - 18

c = 3d - 27
4d + 10c = 120

Thanks, hope someone helps

I will do one problem and let you do the other.

c = 3d - 27
4d + 10c = 120

4d + 10(3d - 27) = 120

4d + 30d - 270 = 120

34d = 390

d = 11.47

c = 3d - 27

c = 34.41 - 27 = 7.41

Check

4d + 10c = 120

4(11.47) + 10(7.41) = 120

45 + 74.1 = 120 (close, probably not exact due to rounding error. Even so, this shows the process.)

I hope this helps. Thanks for asking.

Start paying attention in class and don't be afraid to ask the teacher a question it might sound stupid but your not the only one who dosent get it you know what i mean

To solve each system using the method of substitution, we need to solve one of the equations for one variable and then substitute that expression into the other equation.

1) a = (2/5)b - 3
a = 2b - 18

To solve this system, let's solve the first equation for "a" in terms of "b":
a = (2/5)b - 3

Now, we can substitute this expression for "a" in the second equation:
(2/5)b - 3 = 2b - 18

Next, we can simplify and solve for "b":
(2/5)b - 2b = -18 + 3
(2/5)b - (10/5)b = -15/5
(-8/5)b = -15/5
b = (-15/5) / (-8/5)
b = (-15/5) * (5/8)
b = -3/8

Now we have the value of "b". Let's substitute it back into the first equation to find "a":
a = (2/5)(-3/8) - 3
a = -6/40 - 120/40
a = -126/40
a = -63/20

So, the solution to this system is: a = -63/20 and b = -3/8. To check if this solution is correct, substitute these values back into the original equations and see if they hold true.

2) c = 3d - 27
4d + 10c = 120

Let's solve the first equation for "c" in terms of "d":
c = 3d - 27

Now, substitute this expression for "c" in the second equation:
4d + 10(3d - 27) = 120

Simplify and solve for "d":
4d + 30d - 270 = 120
34d = 390
d = 390/34
d ≈ 11.47

Now, substitute this value of "d" in the first equation to find "c":
c = 3(11.47) - 27
c = 34.41 - 27
c ≈ 7.41

So, the solution to this system is: c ≈ 7.41 and d ≈ 11.47. Again, we should check if these values satisfy the original equations.

I hope this helps! Let me know if you have any further questions.