Answer:
Molly would be 1 years old.
Step-by-step explanation:
"In three years..."
(m+3) will be Molly's age then.
(h+3) will be Heidi's age then.
(h+3) = 2(m+3) :: given.
.
Subsitute what we know about m, which is it equal h-4.
.
(h+3) = 2(m+3)
(h+3) = 2m + 6
substitute m=h-4
(h+3) = 2(h-4) +6
h +3 = 2(h -4) +6
h +3 = 2h -8 +6
h +3 = 2h -2
h = 2h -8 +3
-h = -5
h = 5
Heidi is 5 years old now.
.
m = h-4
m = 5-4
m = 1
Molly is 1 years old now.
Answer:
D
Step-by-step explanation:
142 ÷ 2 = 71
D. ( 100÷2) + (40÷2) + (2÷2)
50 + 20 + 1
71
Answer:
85
Step-by-step explanation:
alternate exterior angles
In this problem, you're looking for the value of t, so that f(t) = 48. That means if you put t into 5t-7, you'll get 48. To do this set up and solve an equation for t by setting 48 equal to 5t-7:

Isolate the variable by adding 7 to both sides.

Divide by 5 on both sides to find t.

The answer is 11.
Answer:
c=80
Step-by-step explanation:
Based on my reading the critical damping occurs when the discriminant of the quadratic characteristic equation is 0.
So let's see that characteristic equation:
20r^2+cr+80=0
The discriminant can be found by calculating b^2-4aC of ar^2+br+C=0.
a=20
b=c
C=80
c^2-4(20)(80)
We want this to be 0.
c^2-4(20)(80)=0
Simplify:
c^2-6400=0
Add 6400 on both sides:
c^2=6400
Take square root of both sides:
c=80 or c=-80
Based on further reading damping equations in form
ay′′+by′+Cy=0
should have positive coefficients with b also having the possibility of being zero.