The equation should be g/12 = 1/4. Since the sub was cut into 12 parts, then the total would have been divided by 12 to get 1/4 equal parts. To solve the equation you multiply 12 by 1/4. This will get you 3. This means the original sub was 3 feet long.
SHORT ANSWER: 84cm
Let width = w
Let length = w + 5
The area of a rectangle is found by multiplying its width by length and the problem states that the area is 84 cm2.
(Width)(Length) = 84
(w)(w + 5) = 84
w2 + 5w = 84
w2 + 5w - 84 = 0
(w + 12)(w -7) = 0
w + 12 = 0
w = -12
The width of a rectangle can't be NEGATIVE!!! Forget about that!
w - 7 = 0
w = 7
Now go back to naming the variables and replace the w with 7.
Length = w + 5 = 7 + 5 = 12
Width is 7 cm. Length is 12 cm.
Check it. Is 7 x 12 = 84? Yes.
Answer:
Step-by-step explanation:
Answer:
3156
Step-by-step explanation:
- <em>Used formula:</em>
- <em>(1² + 2² + 3² + ... + n²) =1/6*n(n + 1)(2n + 1)</em>
--------
- 10²+12²+14²+......+26² =
- (2*5)²+(2*6)² + (2*7)² + ... + (2*13)² =
- 4*(5²+6²+7²+...+13²) =
- 4*(1²+2²+...+13² - (1²+2²+3²+4²)) =
- 4*(1/6*13(13+1)(2*13+1) - (1+4+9+16)) =
- 4*(1/6*13*14*27- 30) =
- 4*(819 - 30) =
- 4*789 =
- 3156
Each "contour" is a pair of parallel lines with slope 8.
