Answer:
I
Step-by-step explanation:
3x-5+7x+5+90=180
x=9
So Annette's speed was 45 mph.
Let's make 2 equations to represent Annette's speed.
T*S = 120
Where
T = the time Annette has been driving.
S = her mean speed.
120 = number of miles she's traveled.
and another equation that's
T*(S+3) = 128
So we now have 2 equations with 2 unknowns. They are
T*S = 120
T*(S+3) = 128
Let's divide the top equation by S on both sides and the bottom equation by (S+3) on both sides giving
T = 120/S
T = 128/(S+3)
So we now know that 120/S is equal to 128/(S+3). So let's make that equation and solve for S
120/S = 128/(S+3)
Multiply both sides by S(S+3)
120(S+3) = 128S
Distribute the 120 on the left
120S + 360 = 128S
Subtract 120S from both sides
360 = 8S
And divide both sides by 8
45 = S
So Annette's speed was 45 mph.
Miles, yards, feet, inches
Answer:
1. Roy
2. k = 15
Step-by-step explanation:
equation 5 ÷ 1/3 = k
Jill k x 1/3 = 5 √
Roy k x 5 = 1/3 x
Ted 5 = 1/3 x k √
solving the equation
k = (5 x 3) / 1
k = 15
