Are you able to ask your teacher?
Answer:
If I read this right
3 (n -12) + 14 = 4 (7 - 5n)
First, remove the parentheses
3 n - 36 + 14 = 28 - 20 n
Combining terms
23 n = 28 - 14 + 36 = 50
n = 50 / 23 = 2 4/23 = 2.17
a) This part is already complete I think..
b) This is a cuboid and lateral surface area of cuboid is: 2(lb +bh + hl)
= 2( 10 × 3 + 3 × 7 + 7 × 10)
= 2(30 + 21 + 70)
= 2 × 121 = 242 cm²
Now, the area of top & bottom: lb
= 2 × 10 × 3
= 60 cm²
Neglecting the top & bottom surface area of cuboid:
= 242 - 60
= 180 cm²
c) The total surface area us 242.. I have already done that part above...
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If i have done something wrong.. please lemme know :)
First you need to find the common denominator. Think of a number that both 2 and 5 can go in to evenly. 10 is the best number, so, make both denominators 10. What you do to the bottom, you must do to the top.
Now your equation is 5/10-2/10
Your answer is 3/10
18% I believe. Because you do the math then you rounded out and then I get 18%