Answer:
Look at the equations:
y
=
−
9
x
−
21
and
y
=
5
x
+
7
Because both equations equal (y), they both equal the same.
If an equations says "
y
=
−
9
x
−
21
" , that means we can replace (y) with
−
9
x
−
21
.
Therefore when i take the equation:
y
=
5
x
+
7
, we can replace (y) to get:
−
9
x
−
21
=
5
x
+
7
Now isolate (x):
−
9
x
−
21
=
5
x
+
7
⇔
−
21
=
14
x
+
7
⇔
−
28
=
14
x
⇔
x
=
−
2
Answer:
t=v/d
Step-by-step explanation:
id think that there are two steps
v=d/t
divide D on both sides
v/d=d/t/d
v/d=t
Answer:
Step-by-step explanation:
(a) Rename h(x) as y
(b) Solve for x :
(d) Switch x and y
(e) Rename y as the inverse function
The graphs of inverse functions are reflections of each other across the line y = x.
In the diagram, the graph of h⁻¹(x) is the reflection of h(x) about the line y = x.
Answer:
A1) 125
A2) 47.5%
B) 30
Step-by-step explanation:
Remember 'of' in this sentence means times(*). % shows a certain number/100.
a1) 48% 'of' what number is 60?
(let unknown number be x)
48/100 *x=60
Solve the equation, and the answer is x=125
a2) what percentage 'of' 120 is 57?
(let the unknown percentage be x)
(x/100)*120=57
x=47.5%
b) 24 students= 80% of the total number of students
1%=24/80
100% of the total number of students=30
So, there are total of 30 students
Answer:
2.5 miles
Step-by-step explanation:
The relation between time, speed, and distance is ...
distance = speed × time
We can define t to be Stanley's swimming time. Then t+0.5 was his running time, and 2(t+0.5) was his biking time. His total distance covered is ...
64 = 9(t +0.5) +16(2(t +0.5)) +2.5(t)
64 = 43.5t +20.5 . . . . . . . simplify
43.5 = 43.5t . . . . . . . . . subtract 20.5
t = 1 . . . . . . . . . . . . . . divide by the coefficient of t
Stanley swam for 1 hour, so the distance he covered while swimming was ...
(2.5 mi/h)(1 h) = 2.5 mi
Stanley covered 2.5 miles while swimming.
_____
<em>Additional comment</em>
Stanley ran for 1.5 hours, covering 9×1.5 = 13.5 miles. He biked for 3 hours, covering 16×3 = 48 miles. His total distance was 2.5 +13.5 +48 = 64 miles, as given.
