Answer:
x = -4, 5/2
Step-by-step explanation:
A quadratic can be solved may ways, including graphing, factoring, and the quadratic formula. You can also check possible answers by making use of the relationships between solutions and the coefficients.
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A graph is attached. It shows the solutions to be -4 and 5/2.
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When factored, the equation becomes ...
(2x -5)(x +4) = 0 . . . . . has solutions x=-4, x=5/2 (these make the factors zero)
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Using the quadratic formula, the solutions of ax^2 +bx +c = 0 are found from ...
x = (-b±√(b²-4ac))/(2a)
x = (-3±√(3²-4(2)(-20))/(2(2)) = (-3±√169)/4 = {-16, +10}/4
x = {-4, 5/2}
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For ax^2 +bx +c = 0, the solutions must satisfy ...
product of solutions is c/a = -20/2 = -10
Only the first and last choices have this product.
sum of solutions is -b/a = -3/2
Only the first choice (-4, 5/2) has this sum.
Answer:
x=17
Step-by-step explanation:
Answer:
17.7 cm^2
Step-by-step explanation:
Use trig to find the height of the triangle. Then the area is bh/2.
Extend side BC to the right until it is vertically below point A. Draw a segment from point A vertically down until it intersects the extension of side BC. Call the point of intersection D. <D is a right angle.
Use triangle ABD to find the height, AD, of triangle ABC.
For <B of 37 deg, AD is the opposite leg. AB is the hypotenuse. The trig ratio that relates the opposite lefg to the hypotenuse is the sine.
sin B = opp/hyp
sin 37 deg = AD/13.1
AD = 13.1 * sin 37 deg
AD = 7.9
AD is the height of triangle ABC. BC is the base. We can find the area of triangle ABC.
area = bh/2
area = (4.5 cm)(7.9 cm)/2
area = 17.7 cm^2
The answer would be ×>5 because when u divide by a negative the sign will switch.