She worked 9 hours at baby-sitting and 6 hours at her parents store.
Step-by-step explanation:
Let,
Baby-sitting hours = x
Hours at parents store = y
Total hours = 15
Amount earned = $93
According to given statement;
x+y=15 Eqn 1
5x+8y=93 Eqn 2
Multiplying Eqn 1 by 5;
Subtracting Eqn 3 from Eqn 2;
Dividing both sides by 3;
Putting y=6 in Eqn 1
She worked 9 hours at baby-sitting and 6 hours at her parents store.
Keywords: linear equations, subtraction
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Step-by-step explanation:
it follows the same structure on the x-axis as cosine, but the curve is stretched up an down to reach values between -5 and +5 instead of between -1 and +1
Answer: the cost of one package of macadamia nut chip cookie dough is $1.5
the cost of one package of triple chocolate cookie dough is $2.5
Step-by-step explanation:
Let x represent the cost of one package of macadamia nut chip cookie dough.
Let y represent the cost of one package of triple chocolate cookie dough.
Mrs. Julien’s class sold 25 packages of macadamia nut chip cookie dough and 30 packages of triple chocolate cookie dough for a total of $112.50. This means that
25x + 30y = 112.5 - - - - - - - - - - - - -1
Mrs. Castillejo’s class sold 8 packages of macadamia nut chip cookie dough and 45 packages of triple chocolate cookie dough for a total of $124.50. This means that
8x + 45y = 124.5 - - - - - - - - - - -2
Multiplying equation 1 by 8 and equation 2 by 25, it becomes
200x + 240y = 900
200x + 1125 = 3112.5
Subtracting, it becomes
- 885y = - 2212.5
y = - 2212.5/- 885
y = 2.5
Substituting y = 2.5 into equation 1, it becomes
25x + 30 × 2.5 = 112.5
25x + 75 = 112.5
25x = 112.5 - 75 = 37.5
x = 37.5/25 = 1.5
The method used is the elimination method. It is more convenient to use.
