4(x+7)=8x-20
4x+28=8x-20
28=4x-20
48=4x
x=12
Answer:
Step-by-step explanation:
A rectangle had a length of 2x-7 and a width of 3x+8y
Perimeter P = 2(l + w)
P = 2(2x - 7 + 3x + 8y)
P = 2(5x + 8y - 7)
P= 10x + 16y - 14
Answer:
28
Step-by-step explanation:
40% 6th graders of 70 total = 28 6th graders
40% 6th graders + 20% 7th graders = 60%
100% - 60% = 40% 8th graders
40% are 8th graders therefore the answer is 28
Let b and s be the velocity of the boat and stream respectively....
3(b-s)=27
b-s=9
b=9+s we will use this in the second equation....
2(b+s)=30
b+s=15, now use b found above in this to get:
9+s+s=15
2s+9=15
2s=6
s=3, and since from earlier b-s=9, b=9+s so
b=12
So the speed of the boat is 12mph and the stream is 3 mph
Just work through step by step
Follow each point until you reach one answer
Digits = 7
-9 = reverse
16 - 9 = 7 x
25 - 9 = 16 x
34 - 9 = 25 x
43 - 9 = 34 Y
52 - 9 = 43 x
61 - 9 = 52 x
4 + 3 = 7
43 - 9 = 34 - the digits have been reversed
43
