Answer:
Step-by-step explanation:
Area of circle:
<em>area = π · r · r</em>
<em>Radius= </em>
= 8
= 200.96 
<em></em>
Based on the numbers we have we can assume that she saves 3 times more each week than the last (1*3=3, 3*3=9).
Following this trend we would multiply the amount she saved the third week ($9) by 3 to get $27 for the fourth week.
Then, we would multiply the amount she saved the fourth week ($27) by 3 to get $81 for the fifth week.
Finally, to figure out how much she saved in the 5 weeks, we need to add each value up to get 1+3+9+27+81= $121 saved in 5 weeks
4-7x= 39
Subtract 4 from both sides
-7x= 35
Divide both sides by -7
x= -5
The value of x+1= (-5)+1= -4.
Average speed = total distance divided by total time.
In the first part, the car covered 490 km in 7 hours, but I think you mistyped the second part (“then covers a speed of 90km”) and a critical piece is missing to find the total distance and time.