Ok here is how you do this:
you need to replace y with 20 and then solve to find x, i.e. solve this equation
20=2/5x
1. Simplify 2/5x to 2x/5
20=2x/5
2. Multiply both sides by 5
20 * 5=2x
3. Simplify 20 * 5 to 100
100=2x
4. Divide both sides by 2
100/2=x
5. Simplify 100/2 to 50
50=x
6. Switch sides
x=50
so your answer is B. 50
I hope this helped!
Answer:
4a^2-19ab-5b^2
Step-by-step explanation:
What you do is the FOIL process.
F=First. The first thing that you do is times 4a and a together to get 4a^2.
O=Outer. You multiply the outer numbers 4a and -5b together to get -20ab.
I=Inner. You multiply the inner numbers b and a together to get ab.
L=Last. You multiply the last numbers b and -5b together to get -5b^2.
Put it all together to get 4a^2-19ab-5b^2 as your answer.
Answer:
The measure of angle F is 67.6°
Step-by-step explanation:
In the right triangle DEF
∵ ∠E is the right angle
∵ Side DF is opposite to ∠E
∴ DF is the hypotenuse of the triangle DEF
∵ Side EF is the adjacent side of ∠F
∵ The cosine ratio = 
∴ cos∠F = 
∵ EF = 8 units
∵ DF = 21 units
→ Substitute them in the cosine ratio above
∴ cos∠F = 
→ Use 
to find the measure of angle F
∵ m∠F = 
∴ m∠F = 67.60731219 degrees
→ Round it the nearest tenth of a degree
∴ m∠F = 67.6°
∴ The measure of angle F is 67.6°
Multiply the blue numbers
I think not so sure
