A + b = 15 ..... eq 1
a – b = 12 ...... eq 2
So a = 15 – b
Substitute in eq 2 :
15 – b – b = 12
15 – 2b = 12
–2b = 12 – 15
b = 1.5
So a = 15 – 3/2 = 13.5
4ab = 4 x 13.5 x 1.5 = 81
Answer:
280 hours
Step-by-step explanation:
Amount paid + profit = cost of a lesson per hour
$2000 + $5000 = $25(h)
7000 = 25h
7000/25 = h
280 = h
9 because the symbols around -12 and -3 so they would just become positive number 12 and 3. Subtract them and you get 9 :)
6.
the y-intercept is 4, which means the line crosses the y-axis at the point (0,4).
[just put a dot on the number four that's right under the letter y]
the slope of the line is positive, so it goes up from left to right.
Start at the y-intercept. Move up 2 and then move right 1.
You are now at the point (1,6).
[go to 1 for the horizontal line, then go up 6 spaces.] [connect two points]
7. y= -1/2-3
8. y=3x+4
The person walked a distance of 120 kilometers in a time 3 hours. (Correct choice: C)
<h3>What is the length of the path covered by a person?</h3>
Herein we have the case of a person walking during a total time of three hours, whose conditions are explained mathematically by the following formula:
x = x / 3 + x / 4 + (x / 3 + 10)
x = (2 / 3) · x + x / 4 + 10
x = (11 / 12) · x + 10
x / 12 = 10
x = 120
The person walked a distance of 120 kilometers in a time 3 hours. (Correct choice: C)
To learn more on linear equations: brainly.com/question/11897796
#SPJ1
