Answer:
Yumiko should multiply the other equation by 3.
If she adds the two equations she would be left with the variable 'x'.
Step-by-step explanation:
Given the two equations are as follows:
It is given that she multiplies the first equation by 6. Therefore, (1) becomes
Now, note that the sign of the variable 'y' is negative. So, if we make the co-effecient of 'y' equal in both the cases, add them it would result in the elimination of the variable 'y'.
The co-effecient of y in Equation (2) is 6. To make it 18 like it is in Equation (1), we multiply throughout by 3.
Therefore, Equation (2) becomes:
Now, we add Equation (a) and Equation (b).
Factor: 3
Equation: 27x = 126
Answer:
x=3 and x=-1.25
Step-by-step explanation:
4x^2-7x=15
subtract 15 from each side:
4x^2-7x-15=0
factor (trying different numbers that the sum is 7 and the quotient is 15)
(2x-6 )(2x+2.5 )=0
2x-6=0 add 6 to each side
2x=6
x=3
2x+2.5=0 subtract 2.5 from each side
2x=-2.5
x=-1.25
Answer:
Proportioal
Step-by-step explanation:
?
Using a scientific calculator:
log 12 = 1.079181246
Rounded to four decimal places:
log 12 = 1.0792
Characteristic: 1; Mantis: 0.0792
Answer: OPtion B. 1.0792; 1; 0.0792
Let dimes = d and quarters =q
D + q = 50
D= 50-q
0.10d + 0.25Q = 7.70
Replace d with 50-q:
0.10(50-q) + 0.25q = 7.70
Simplify:
5 -0.10q + 0.25q = 7.70
5 + 0.15q = 7.70
Subtract 5 from both sides:
0.15q = 2.70
Divide both sides by 0.15:
Q = 2.70 / 0.15
Q = 18
D = 50-18 = 32
There are 32 dimes and 18 quarters
