The error is in the first step. It should be (+8 plus or minus the square root of the quantity eight squared minus four times one times seven ). This is because "b" is -8 so -b is -(-8) = +8
Answer:
11 marbles
Step-by-step explanation:
Let x = no. of marbles-Alex
3x = no. of marbles-Billie
3x - 9 = no. of marbles-Chris
x + 3x + 3x - 9 = 68
7x - 9 = 68
7x = 77
x = 11
180-112\2. the answer is 34°.
C.2x+2+3x because you have 2x’s a 2 and 3 w’s