Answer:
6 hours
Step-by-step explanation:
Let
x----> the number of hours worked at the donut shop
y----> the number of hours worked at the school bookstore
we know that
x+y=20
x=20-y -----> equation A
10.25x+8.75y=196 -----> equation B
Substitute equation A in equation B and solve for y
10.25(20-y)+8.75y=196
205-10.25y+8.75y=196
10.25y-8.75y=205-196
1.5y=9
y=6 hours at the school bookstore
Answer:
Step-by-step explanation:
Let's write the left hand side as a negative power, and 9 as a power of 3:
At this point, for the equality to still stand, the exponents have to be equal:
<u>Answer</u>
2,268
<u>Explanation</u>
<u>
</u>
<u>By grouping 378 ca</u>n be written as,
378 = 300 + 70 + 8
6× 378 = 6 × (300 + 70 + 8)
= (6×300)
+ (6×70) + (6×8)
= 1800
+ 420 + 48
= 2,268
<span>sinx - cosx =sqrt(2)
Taking square on both sides:
</span>(sinx - cosx)^2 =sqrt(2)^2<span>
sin^2(x) -2cos(x)sin(x) + cos^2(x) = 2
Rearranging the equation:
sin^2(x)+cos^2(x) -2cos(x)sin(x)=2
As,
</span><span>sin^2(x)+cos^2(x) = 1
</span><span>So,
1-2sinxcosx=2
1-1-2sinxcosx=2-1
-</span><span>2sinxcosx = 1
</span><span>Using Trignometric identities:
-2(0.5(sin(x+x)+sin(x-x))=1
-sin2x+sin0=1
As,
sin 0 = 0
So,
sin2x+0 = -1
</span><span>sin2x = -1</span><span>
2x=-90 degrees + t360
Dividing by 2 on both sides:
x=-45 degrees + t180
or 2x=270 degrees +t360
x= 135 degrees + t180 where t is integer</span>
