Answer:
He determined pounds per dollar by dividing 10 by 25 but wrote the unit rate as a dollar value.
Step-by-step explanation:
Given
Required
Determine Ming's error
Ming's error is from here
He calculated the unit rate as pound per dollar.
So, after calculating the unit rate, the unit should be:
But instead, he solved as:
<em>Hence, (a) is correct</em>
Answer:
Step-by-step explanation:
x = measure of the first angle
y = measure of the second angle
z = measure of the third angle
The sum of the measures of the second and third (y+z) is five times the measure of the first angle (=5x)
The third angle is 14 more than the second
And remember that the sum of these three angles must be equal to 180.
Let's take these equations
If you take a look at the first equation, we have y+z = 5x and we have y+z in the third equation as well, we can replace that....
Distribute the + sign
Combine like terms;
Divide by 6.
We have now defined that the measure of the first angle is 30º.
Let's take another equation... for example
I'm going to take this one because if I replace x and z in the third equation, all I'll have left will be y.
Distribute the + sign and Combine like terms;
Subtract 44 to isolate 2y.
Now divide by 2.
We already have the value of x and y. Once again, replacing this in the third equation will leave us with z to solve for.