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
Step-by-step explanation:
I'm maths but o and sassess sees A ooooooobbbbbbnsnsndnsnsnnsndhshdhdhdd
b
Step-by-step explanation:
i just graphed each of them and b was the one that look most similar
20
If you draw that out on a coordinate grid, you get a trapezoid with one base 6 units long, one base 4 units long and a height of 4. Using the formula for area of a trapezoid
h(b1 + b2)/2
where h is the height, 4, b1 is a base, 6, b2 is the other base, 4, we get
4(4+6)/2
which is 4(10)/2 or 40/2
which gets us the answer, 20
Part/Whole=Percent/100
Part=26
Whole=30
Percent= Variable because that is what you want to find out
So now it is 26/30=X/100
You then cross multiply and you get
2600=30X
Divide by 30 and your answer is 86.66667. She got 86.66667% of her questions right. I am not sure if you need to round that or not.
Another way you can do it is Divide 26÷30=.866667 and then multiply by 100 to get 86.66667.
