7(3a + 12) = 168 ← ( divide both sides by 7 )
3a + 12 = 24 ← ( subtract 12 from both sides )
3a = 12 ← ( divide both sides by 3 )
a = 4
OR
distribute the parenthesis by 7
21a + 84 = 168 ← ( subtract 84 from both sides )
21a = 84 ← ( divide both sides by 21 )
a = 4
The first step to solving a story problem is identifying variables. For this problem, I will identify the variables as:
D = Drew's age
J = Jimmy's age
Once the variables are identified, we need to find as many equations as we have variables. Since we have two variables, we will have to write two equations.
Since Drew is 3 years younger than Jimmy: D + 3 = J
Since the sum of the brothers' ages is 21: D + J = 21
Once I have two equations is two variables, I can solve the system using either substitution method or elimination method. For this problem, I will use substitution method.
D + J = 21 Equation 2
D + (D + 3) = 21 Substitution of value of J from equation 1 into equation 2
D + D + 3 = 21 Associative property of addition
2D + 3 = 21 Simplify
2D + 3 - 3 = 21 - 3 Subtract 3 from each side
2D = 18 Simplify each side
2D/2 = 18/2 Divide each side by 2
D = 9 Simplify each side
Now that we have D, we can substitute it into equation 1 to get the value of J
D + 3 = J Equation 1
9 + 3 = J Substitution
12 = J Simplify
Answer: 90
Step-by-step explanation: We know that, every 20 shots he attempts, he makes 18. He has a 90% success rate. If he attempts 100 free throws, he would make 90% of them, which is 90!
Another way to solve it is note that 100 is 20*5, so 18*5 is 90, which is also our answer.
Answer:
7p¹⁵/ 3q¹²
Step-by-step explanation:
From the question given above,
28p⁹q¯⁵ / 12p¯⁶q⁷
To know which of option is equivalent to the above expression, we shall simplify the expression as shown below:
28p⁹q¯⁵ / 12p¯⁶q⁷
28p⁹q¯⁵ ÷ 12p¯⁶q⁷
Recall:
Xᵐ ÷ Xⁿ = Xᵐ ¯ ⁿ
Therefore,
28p⁹q¯⁵ ÷ 12p¯⁶q⁷ = (28/12)p⁹ ¯ ¯⁶q¯⁵ ¯⁷
28p⁹q¯⁵ ÷ 12p¯⁶q⁷ = (7/3) p⁹⁺⁶q¯¹²
28p⁹q¯⁵ ÷ 12p¯⁶q⁷ = (7/3) p¹⁵q¯¹²
Recall:
X¯ⁿ = 1/Xⁿ
Therefore,
(7/3) p¹⁵q¯¹² = (7/3) p¹⁵ × 1/q¹²
(7/3) p¹⁵q¯¹² = 7p¹⁵/ 3q¹²
Hence,
28p⁹q¯⁵ / 12p¯⁶q⁷ = 7p¹⁵/ 3q¹²
Answer:the answer would be C
Step-by-step explanation:
