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:
5.58*10^7
Step-by-step explanation:
Recall that 10^a*10^b = 10^(a+b). Thus, 10^5*10^2 = 10^7.
Thus, (1.8 x 10^5)(3.1 x 10^2) = (1.8)(3.1)*10^7 = 5.58*10^7
9 is in parentheses therefore it's elevated above 3 that means you have to do operations on it first.
3 + (-9) = -6
The sum is negative.
Answer:
x = -4
Step-by-step explanation:
Distribute:
-2(x + 5) = -2
-2(x) -2(5) = -2
Multiply:
-2(x) -2(5) = -2
-2x - 10 = -2
Add 10 on both sides:
-2x - 10 = -2
+10 +10
-2x = 8
Divide by -2 on both sides:
-2x = 8
/-2 /-2
x = -4
