Answer:
2 x = 5 2x=5 2x=5. 2x=5. 2x=5. 2x=5. 1. Divide both sides by 2 2 2. x = 5 2 x=\frac{5}{2} x=25. Done. Decimal Form: 2.5. Check Answer ▽. x=5/2.
Step-by-step explanation:
Answer:
4th is correct answer. 1, 2, 3 not correct you can check the exponents properties
Answer:
Sister = 15 years old
Brother = 12 years old
Step-by-step explanation:
Right now, if the brother is B years old and the sister is S years old, B = (4/5)S because the ratio from brother to sister is 4:5, so if one unit is X, B = 4X and S = 5X
Three years ago, the brother was B-3 years old and the sister was S-3 years old. Keeping one unit as X, we have
B = 3X
S = 4X
B-3 = (3/4)(S-3)
Therefore, we have a system of equations
B = (4/5)S
B-3 = (3/4)(S-3)
Substitute (4/5)S for B into the second equation to only have one variable
(4/5)S - 3 = (3/4)(S-3)
(4/5)S - 3 = (3/4)S - 9/4
add 3 to both sides and subtract (3/4)S from both sides to isolate the variable and its coefficient
(1/20)S = 3/4
multiply both sides by 20 to isolate the S
S = 15
B = (4/5)S = 12
We can use the is/of=p/100 method for this problem. Since it's 15% off, this would mean that the bill is 85% of what it was initially. Plug the values into the is/of=p/100 formula.
36.72/x = 85/100
Solve for x.
x=36.72/0.85
x=43.2
So, the bill was $43.20 before applying the voucher discount of 15% off.
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