Let's say her speed was x miles/hour during the first 3 miles runThen, time = distance/speedt1 = 3/x eq1 In the next 4 miles run, her speed = x-1 miles/hourTime taken:t2 = 4/(x-1) eq2 Now, total time:t1 + t2 = 1 3/5 hourssubstitute t1 and t2 from eqs. 1 and 2 3/x + 4/(x-1) = 1 3/5=> 3/x + 4/(x-1) = 8/5
=> 3(x-1) + 4x = 8x(x-1)/5=> 35x - 15 = 8x2 - 8x=> 8x2 - 43x + 15 = 0=> (8x-3)*(x-5) = 0=> x = 3/8 or 5 miles/hourx can not be 3/8 miles/hour because in that case, the speed during 4 miles run would be 3/8-1 = negative numberi.e. speed during 3 miles segment = 5 miles/hourand speed during 4 miles segment = 5-1 = 4 miles/hour
<u>Answer:</u>
143°
option c is correct!
<u>Explanation:</u>
Given:
Two angles are supplementary:
One angle = 37°
We know if two angles are supplementary their sum is equal to 180°.
Let another angle be x°
= > 37° + x° = 180
= > x° = 143°
Therefore another angle is 143°.
Answer:
C. 60
Step-by-step explanation:
x + 10 = 70
Subtract 10 from both sides
x + 10 - 10 = 70 -10
Simplifying
x = 60
Answer:
x = 10.4
Step-by-step explanation:
1. Multiply each side by 5 to remove it as a fraction
2. it cancels out on the left leaving 10x - 4 = 100
3. Add 4 to each side canceling it out on the left and leaving 10x = 104
4. Divide each side by 10 to get x by itself
5. 10x/100 = 104/10
6. x = 10.4
<span>Many simple inequalities can be solved by adding, subtracting, multiplying or dividing both sides until you are left with the variable on its own.But these things will change direction of the inequality: ...<span>Don't multiply or divide by a variable (unless you know it is always positive or always negative)</span></span>
