Answer:
Stacy used 32 Blue beads
Explanation:
Lets call: B the quantity of Blue beads used in the necklace and R the quantity of Red beads used in the necklace.
From the sentence: Stacy made a necklace using 4 times as many blue beads as red beads, we can formulate the following equation:
equation 1: B = 4*R
Then, from the sentence: She used a total of 40 beads, we can formulate the following equation:
equation 2: B + R = 40
So, for find the values of B and R, we can replace the equation 1 on equation 2 and solve for R, as:
(4*R) + R = 40
5*R = 40
R = 40/5
R = 8
Replacing the value of R on equation 1, we get:
B= 4*8 = 32
Finally the quantity of Blue Beads used in the necklace is 32