We are given with the rate of change of the base, db/dt equal to 1 ft/ sec and the rate of change of the height of the triangle, dh/dt equal to 2 ft/sec. b is 10 ft and h is 70 ft. Area of triangle is equal to A= 0.5 bh The rate of change of the area is equal to dA/dt = 0.5 b dh/dt + 0.5 h db/dt. Substituting, dA= 0.5*10*2 + 0.5*70 * 1 equal to 45 ft2 / sec.
Answer:
<h2>x =
-2+i√5 and -2i-√5</h2>
Step-by-step explanation:
The general form of a quadratic equation is ax²+bx+c = 0
Given the quadratic equation x²+4x+9=0 in its standard form, on comparing with the general equation we can get the value of the constant a, b and c as shown;
ax² = x²
a = 1
bx = 4x
b = 4
c = 9
The quadratic formula is given as x = -b±√(b²-4ac)/2a
Substituting the constant;
x = -4±√(4²-4(1)(9))/2(1)
x = -4 ±√(16-36)/2
x = -4±√-20/2
x = -4±(√-1*√20)/2
Note that √-1 = i
x = -4±(i√4*5)/2
x = (-4±i2√5)/2
x = -4/2±i2√5/2
x = -2±i√5
The solution to the quadratic equation are -2+i√5 and -2i-√5
Answer:
x = 29
Step-by-step explanation:
If the equation is :
4.2(9-x)+36=102-2.5(2x+2)
→distribute 4.2 and -2.5 in parenthesis
4.2(9 - x) + 36 = 102 -2.5(2x + 2)
37.8 - 4.2x +36 = 102 -5x -5
→ have terms with x = terms without x
Keep the terms you need the way they are, and move the terms you need on the other side of equal sign with changed sign.
4.2(9 - x) + 36 = 102 -2.5(2x + 2)
37.8 - 4.2x +36 = 102 -5x -5
- 4.2x +5 x = - 37.8 - 36 + 102 - 5
→ Combine like terms
0.8x = 23.2
→ Divide both sides by 0.8
x = 29
