6x - 3y = 15.....multiply by 4
7x + 4y = 10....multiply by 3
---------------
24x - 12y = 60 (result of multiplying by 4)
21x + 12y = 30 (result of multiplying by 3)
---------------add
45x = 90
x = 90/45
x = 2
6x - 3y = 15
6(2) - 3y = 15
12 - 3y = 15
-3y = 15 - 12
-3y = 3
y = -3/3
y = -1
solution is (2,-1) <==
Answer:
B
Step-by-step explanation:
Answer:
264cm³
Step-by-step explanation:
Volume of figure
= (3×8×7) + (4×3×8)
= 168 + 96
= 264cm³
Answer:
the surface area of a penny = 662.81 mm²
Step-by-step explanation:
given:
A penny is a cylinder with a diameter of 19.05 millimeters
and a thickness of 1.55 millimeters.
find:
what is the surface area of a penny?
<u>surface area of a cylinder formula:</u>
As = 2 π r h + 2 π r²
let r = 19.05 / 2
r = 9.53 mm
let h = 1.55mm
plugin values into the formula:
As = 2 π (9.53) 1.55 + 2 π (9.53)²
As = 92.76 + 570.05
As = 662.81 mm²
therefore,
the surface area of a penny = 662.81 mm²
