N= Heidi's marbles
92 - n =18 (Barry's 92 marbles - whatever Heidi has = 18 marbles difference)
92 -n +n = 18 +n (I added n to each side)
92 = 18+n
92 -18 = 18-18 + n (I subtracted 18 from both sides)
74 = n Heidi has 74 marbles
Answer:
8 + 2x
Step-by-step explanation:
You are adding 8 to 2 times an unknown number.
Answer:
x=140/-18
x=-7+7/9
Step-by-step explanation:
-5(4x-2)+2x+1=151
We move all terms to the left:
-5(4x-2)+2x+1-(151)=0
<em>We add all the numbers together, and all the variables</em>
2x-5(4x-2)-150=0
<em>We multiply parentheses</em>
2x-20x+10-150=0
<em>We add all the numbers together, and all the variables</em>
-18x-140=0
<em>We move all terms containing x to the left, all other terms to the right</em>
-18x=140
x=140/-18
x=-7+7/9
Every hour is 60 minutes, there is 43 minutes before 12:00, and 155 minutes after 12:00
43 + 155 = 198
He was at the museum for 198 minutes, or 3 hour and 18 minutes.
