The three scores are 86, 74, and an unknown score x. The average (i.e. the sum divided by how many there are) is 80, so we have
Multiply both sides by 3 and you get
Subtract 160 from both sides to get
Note: you could solve this exercise very quickly if you notice that the two numbers, 86 and 74, are symmetrical with respect to 80, which is the average. So, the third number must be the average.
Answer:
It is xy
Step-by-step explanation:
Basically Samantha makes six bracelets per hour, so:
After 1 hour she makes 6
After 2 hours she makes 12
After 3 hours she makes 18
After 4 hours she makes 24, therefor the answer is B
This can also be modelled by the equation B = 6t, where B is the number of bracelets and t is the number of hours, so:
B = 6(4) = 24
Answer:
x = 8, and y = 12
Step-by-step explanation:
There are 2 variables, so you need 2 equations to form a system of equations in two variables.
The upper left triangle has all angle measures given: 100, 2x + y, 5x + y. We know that the sum of the measures of the angles of a triangle is 180.
First equation:
100 + 2x + y + 5x + y = 180
Simplify:
7x + 2y = 80 (First equation)
Now we see that the upper and lower sides are parallel, so alternate interior angles are congruent. The angles measuring 2x + y and 5x - y are alternate interior angles and are congruent.
Second equation:
2x + y = 5x - y
Simplify:
3x - 2y = 0 (Second equation)
Now we use the first equation and the second equation as a system of simultaneous equations to solve for x and y.
7x + 2y = 80
3x - 2y = 0
Solve the second equation for 2x.
3x = 2y
Now replace 2y in the first equation with 3x.
7x + 3x = 80
10x = 80
x = 8
Replace x with 8 in the second equation.
3(8) - 2x = 0
24 = 2x
x = 12
Answer: x = 8, and y = 12
The recipe calls for 5/8 cups butter and Angie wants to triple the recipe.
Therefore, if Angie is tripling the recipe, she is multiplying all of the ingredients in the recipe by 3.
So for the butter, this would be:
5/8 * 3 = 15/8
Next, we should turn this improper fraction into a mixed number so that we can compare it to the amount of butter that Angie has.
15/8 = 1 7/8
1 7/8 > 1 1/4
Thus, Angie DOES NOT have enough butter to triple the recipe.
