replace the 1st equation into the 2nd one for y
-8x-4(2x-5) = -20
-8x-8x+20 =-20
-16x+20 = -40
-16x=-40
x = 5/2 = 2.5
y = 2x-5 - 2(2.5) - 5 = 5-5 = 0
one solution (2.5,0)
E and ln are each other's opposite. So the answer is simply 7x
<h2><u>Solution (1)</u> :</h2>
Given, to find A we have to :
- square m
- Add y to m²
- Subtract 7 from m² + y
From the question, the following equation can be formed :

Therefore, the formula for finding A = m² + y - 7
<h2><u>Solution (2)</u> :</h2>
The value of A we can derive from the formula is :

Value of m = 3 (given)
Which means :




Thus, the value of A = 2+y
Therefore, the value of A = <u>2+y</u>
Angle D is 180° -75° -45° = 60°. Drawing altitude MX to segment DN divides the triangle into ΔMDX, a 30°-60°-90° triangle, and ΔMNX, a 45°-45°-90° triangle. We know the side ratios of such triangles (shortest-to-longest) are ...
... 30-60-90: 1 : √3 : 2
... 45-45-90: 1 : 1 : √2
The long side of ΔMDX is 10√3, so the other two sides are
... MX = MD(√3/2) = 15
... DX = MD(1/2) = 5√3
The short side of ΔMNX is MX = 15, so the other two sides are
... NX = MX(1) = 15
... MN = MX(√2) = 15√2
Then the perimeter of ΔDMN is ...
... P = DM + MN + NX + XD
... P = 10√3 +15√2 + 15 + 5√3
... P = 15√3 +15√2 +15 . . . . perimeter of ΔDMN