Answer:
8399
Step-by-step explanation:
78*100=7800
58*10=580
7800+580+19=8399
Answer:
<h3>r =-12</h3>
Step-by-step explanation:
Answer:
u^2 +7u -8=0 where u = 3x+2
Step-by-step explanation:
(3x+2)^2 + 7(3x+2) - 8=0
Let 3x+2 = u
u^2 +7u -8=0
Answer:
18.87 square cm.
Step-by-step explanation:
The area of the rectangle will be (4 + 4) * 4, since the length of the rectangle would be the diameter of the circle, and the width of the rectangle would be the radius. (4 + 4) * 4 = 8 * 4 = 32 square cm.
Then, we can calculate the area of the semicircle. The area of a circle is pi * r^2, so the area of a semicircle will be half of that. pi * (4^2) / 2 = pi * 16 / 2 = 8pi. 8 * 3.14159265 = 25.1327412 square cm.
The shaded area of the middle of the shape will then be 32 - 25.1327412 = 6.8672588 square cm.
The two triangles will have the same area. Their bases will be 14 minus the diameter of the circle, then divide that by 2 to get each separate base. 14 - 8 = 6 / 2 = 3. The heights of the triangles will be the radius of the circle, or 4 cm.
1/2 * 3 * 4 = 1/2 * 12 = 12/2 = 6. That is the area of one triangle, so the area of both triangles would be 6 * 2 = 12 square cm.
6.8672588 + 12 = 18.8672588, or 18.87 square cm.
Hope this helps!
Answer:
m∠DBC is 43°
Step-by-step explanation:
Let us solve the question
∵ D is in the interior of ∠ABC
→ That means D divides ∠ABC into two angles ABD and DBC
∴ m∠ABD + m∠DBC = m∠ABC
∵ m∠ABD = (3x + 5)°
∵ m∠DBC = (5x - 7)°
∵ m∠ABC = 78°
→ Substitute them in the equation above
∴ 3x + 5 + 5x - 7 = 78
→ Add the like terms in the left side
∵ (3x + 5x) + (5 + -7) = 78
∴ 8x + -2 = 78
∴ 8x - 2 = 78
→ Add 2 to both sides
∴ 8x -2 + 2 = 78 + 2
∴ 8x = 80
→ Divide both sides by 8
∴ x = 10
→ To find m∠DBC, substitute x by 10 in its measure
∵ m∠DBC = 5(10) - 7
∴ m∠DBC = 50 - 7
∴ m∠DBC = 43°
