15x²+16x+4 =0 (ax² +bx +c=0)
Δ = b²-4ac =256 - 4×15×4 =16
x1 = (-b+√Δ) / 2a = (-16+√16) / 30 =( -16+4) / 30 = -12/30 = - 2/5
x2 = (-b -√Δ) / 2a = (-16 -√16) / 30 = (-16 -4) /30 = -20/30 = -2/3
Answer:
(294π +448) cm³ ≈ 1371.6 cm³
Step-by-step explanation:
The half-cylinder at the right end has a radius of 7 cm, as does the one on top. Together, the total length of these half-cylinders is 8 cm + 4cm = 12 cm. That is equivalent in volume to a whole cylinder of radius 7 cm that is 6 cm long.
The cylinder volume is ...
V = πr²h = π(7 cm)²(6 cm) = 294π cm³
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The cuboid underlying the top half-cylinder has dimensions 4 cm by 8 cm by 14 cm (twice the radius). So, its volume is ...
V = LWH = (4 cm)(8 cm)(14 cm) = 448 cm³
Then the total volume of the composite figure is ...
(294π +448) cm³ ≈ 1371.6 cm³
The slope is [ 8 - (-1) ] / [ -1 - (-4) ] = 9 / 3 = 3;
The line has the equation: y - 8 = 3( x + 1);
y - 8 = 3x + 3;
y = 3x + 11.
3a + a - 15 = 225 . your substituting b(a-15) into the first equation. <span />