It's 6!
When you multiply both the numerator and denominator by the same number, you will have an equivalent to the fraction you started with because the new fraction can be reduced to the original fraction.
2/3 = 4/6 = 6/9 = 8/12 = 10/15 = 12/15 etc.
Pick 2 pairs of equations t<span>hen use addition and subtraction to eliminate </span>the same variable<span> from both pairs of equations then it is left with 2 variables
</span>Pick two pairs
<span><span>4x - 3y + z = - 10</span><span>2x + y + 3z = 0
</span></span>eliminate the same variable from each system
<span><span>4x - 3y + z = - 10</span>
<span>2x + y + 3z = 0</span>
<span>4x - 3y + z = - 10</span>
<span>-4x - 2y - 6z = 0</span>
<span>-5y - 5z = - 10</span>
<span>2x + y + 3z = 0</span>
<span>- x + 2y - 5z = 17</span>
<span>2x + y + 3z = 0</span>
<span>-2x + 4y - 10z = 34</span>
<span>5y - 7z = 34
</span></span>Solve the system of the two new equations:
<span><span>-5y - 5z = - 10</span>
<span>5y - 7z = 34</span>
<span>-12z = 24</span>
which is , <span>z = - 2</span>
<span>-5y - 5(- 2) = - 10</span>
<span>-5y = - 20</span>
wich is , <span>y = 4
</span></span>substitute into one of the original equations
<span>- x + 2y - 5z = 17</span>
<span>- x + 2(4) - 5(- 2) = 17</span>
<span>- x + 18 = 17</span>
<span>- x = - 1</span>
<span>x = 1</span>
<span>which is , </span><span>(x, y, z) = (1, 4, - 2)</span><span>
</span>Does 2(1) + 4 + 3(- 2) = 0<span> ? Yes</span><span>
</span>
The only thing I can think of to rewrite this is either 8+72t or changing the variable to a different letter. The expression is already in its simplest form.
-2(x + 3) = 8
Multiply -2 with x and 3
-2x -6 = 8
Now add 6 to both sides
-2x -6 = 8
+6 +8
-2x = 16
Lastly divide -2 from both sides to find x
-2x = 16
—— —-
-2x -2x
X = -8
Answer:
<u>9 mph</u>
Step-by-step explanation:
Calvin's first leg of the trip took 0.5 hr (30 minutes) at 6 mph. That means he travelled (0.5hr x 6 mph =) 3 miles. He travelled 3 miles on the return trip, by definition (same path home). At 18 mph, 3 miles would take (3 miles/18 mph =) 0.1667 hours. That makes a total of 6 miles and (0.5 + 0.1667=) 0.6667 hours.
(6 miles)/(0.6667 hours) = 9 mph is Calvin's average speed for the round trip.
