Answer:
A. x = 10 years
B. x = 20 years
Step-by-step explanation:
Given:
y = 0.7(200 - x)
Where,
y = target heart rate in beats per minute
x = person's age in years
How old is a person with a target heart rate of 133 beats per minute?
y = 0.7(200 - x)
133 = 0.7(200 - x)
133 = 140 - 0.7x
133 - 140 = -0.7x
-7 = -07x
x = -7/-0.7
x = 10 years
B. How old is a person with a target heart rate of 126 beats per minute?
y = 0.7(200 - x)
126 = 140 - 0.7x
126 - 140 = -0.7x
-14 = -0.7x
x = -14/-0.7x
x = 20 years
The office must buy 6 5- gallons jugs each month for Best Water to cost less.
5x + 8y = -29
7x - 2y = -67 ..... multiply both sides by 4
5x + 8y = -29
28x - 8y = -268
33x + 0y = -297
x = -9
(-9, 2)
(0,5)(4,0)
slope = (0 - 5) / (4 - 0) = -5/4
y = mx + b
slope(m) = -5/4
use either of ur sets of points....(0,5)...x = 0 and y = 5
now we sub and find b, the y int
5 = -5/4(0) + b
5 = b
so ur equation is : y = -5/4x + 5...but we need it in standard form...
y = -5/4x + 5
5/4x + y = 5....multiply everything by common denominator of 4
5x + 4y = 20 <== standard form of Ax + By = C