Answer:
Joe is 14.
Martha is 28.
Step-by-step explanation:
Use the variables and information from the question to make equations.
If Joe's age is half Martha's:
(1/2)m = j OR 2j = m
If their ages combined is 42:
m + j = 42
We can substitute the equation m=2j into equation m + j = 42, replacing "m".
m + j = 42 Substitute m for 2j
2j + j = 42 Combine like terms, terms with same varables
3j = 42 Divide both sides by 3 to isolate j
j = 14 Joe's age
Since j = 14, we can substitute it into equation m=2j to find "m".
m = 2j Substitute j for 14
m = 2(14) Simplify
m = 28 Martha's age
Therefore Joe is 14 and Martha is 28.
Answer:
y = 
Step-by-step explanation:
Given that y varies directly as x then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = 7 when x = 3
k =
=
, thus
y =
x ← equation of variation
When x = 7, then
y =
× 7 = 
Answer: (C)The square root of terms separated by addition and subtraction cannot be calculated individually.
Step-by-step explanation:
Answer:
-189
Step-by-step explanation:
Remember to follow the rules of signs:
- If there are two positive signs next to each other, you add:
- If there is one negative sign and one positive sign next to each other, you subtract.
- If there is two negative signs next to each other, you add:
- 412 - (-223) = -412 + 223
Subtract:
223 - 412 = -189
-189 is your answer.
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