Answer:
15/31
Step-by-step explanation:
substitute -9 were there's x in the function
f(-9)=2(-9)+3/4(-9)+5
=-18+3/-36+5
=-15/-31
the negatives cancel giving you
15/31
Answer:B
Step-by-step explanation:
If you take 1/3 and multiply it by -6 you get -2 but if you take 1/3 and multiply it by -1 you get -1/3.
So we assume that x=x and y=y is true for both situations so
3x+2y=-2
6x-y=6
6x-y=6
add y to both sides
6x=6+y
subtract 6 from both sides
6x-6=y
subsitute (6x-6) for y in first equation
3x+2(6x-6)=-2
distribute
3x+12x-12=-2
add like terms
15x-12=-2
add 12 to both sides
15x=10
divide both sides by 15
x=2/3
subsitute
3x+2y=-2
3(2/3)+2y=-2
6/3+2y=-2
2+2y=-2
subtract 2 from both sides
2y=-4
divide both sides by 2
y=-2
x=2/3
y=-2
solution in (x,y) form
(2/3,-2)
Answer:
243cm^3
Step-by-step explanation:
By Pythagoras' Theorem,
height of the prism ^2 + 5.4^2 = 7.8^2
height of the prism = ±√(7.8^2 -5.4^2) = ±5.6285cm (5s.f.) (rej. - 5.6285 since height > 0cm)
volume of the prism = 1/2 x 5.4 x 5.6285 x 16 = 243cm^3 (3s.f.)
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