767 rounded to the nearest ten is 770
Answer:
Step-by-step explanation:
Let the speed of Masha = s, speed of Dasha = d
- Distance = 20 km
- Time difference = 20 min = 1/3 hr
- Speed difference = 2 km/h
<u>As per above info we get following equations:</u>
- s = d + 2
- 20/s + 1/3 = 20/d
<u>Substitute s and solve for d:</u>
<u>Get rid of fraction by multiplying all terms by 3d(d + 2):</u>
- 60d + d(d + 2) = 60(d + 2)
- 60d + d² + 2d = 60d + 120
- d² + 2d = 120
- d² + 2d + 1 = 121
- (d + 1)² = 11²
- d + 1 = 11
- d = 10
<u>Find s:</u>
<u>The answer is</u>
- Masha's speed 12 km/h and Dasha's speed 10 km/h
ANSWER

EXPLANATION
To find the expression that is equivalent to

we must first expand

Then we rearrange to find the required expression.
So let's get started.

We expand the parenthesis on the right hand side to get,

We expand again to obtain,

Let us group the cubed terms on the right hand side to get,


We make the cubed terms the subject,

We factor to get,

We expand the bracket on the left hand side to get,

We finally simplify to get,
Step-by-step explanation:
<u>Step 1: Substitute x from the second equation into the second one</u>







<u>Step 2: Substitute y into the second equation</u>




Answer: 
Answer:
Facts.
Step-by-step explanation: