The error Alex made while simplifying the expression 7+(3x 1. 4)+5+2+(5x1. 4) is "he found the perimeter of the figure instead of the area".
<h3>How to find area of an object?</h3>
The area of an object is the product of the length and width of the objects.
Alex added the dimensions of the grid instead of multiplying them.
7+(3x 1. 4)+5+2+(5x1. 4)
For instance,
- Area of a rectangle = length × width
- Perimeter of a rectangle = 2(length + width)
Therefore, Alex found the perimeter of the figure instead of the area".
Learn more about area:
brainly.com/question/13048427
Since the whole thing is 24x+8, it is divided in 2 parts so both of those must be equal to the whole one. You get:
14x-2+70=24x+8
10x=60
x=6
The answer for this is 32
Call the point of intersection of the diagonals point X.
Each base is the hypotenuse of an isosceles right triangle whose sides are the diagonals and whose 90° angle is at X. The altitude of that triangle (⊥ distance to the base from X) is half the length of the hypotenuse. Then the height of the trapezoid is half the sum of the base lengths.
The area of the trapezoid is the product of the height and half the sum of the base lengths, hence is the square of half the sum of the base lengths.
... Area = ((16 cm +30 cm)/2)² = (23 cm)² = 529 cm²
20² = (8 + 8)² + x²
x = 12
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the missing side has a value of 12, found using pythagorean theorem
