Answer:
b) 7.89*10^4
c) 3.15*10^3
Step-by-step explanation:
2-42)
the coefficient in scientific notation (the number that is not 10^x) has to be greater or equal to 1 and less than 10. so c and b are incorrect.
b) 0.789*10^5
c) 31.5*10^2
b) 0.789*10^5
in order to make 0.789 greater than 1, I would just multiply it by 10. shown below
=0.789*10*10*10*10*10
=7.89*10*10*10*10
=7.89*10^4
c) 31.5*10^2
same concept but this time divide by 10 to make 3.15 which will add another *10 to the exponent
=31.5*10*10
=3.15*10*10*10
=3.15*10^3
So
-4x-5y-z=18
-2x-5y-2z=12
-2x+5y+2z=4
the 2 last equations look perfect for canceling each other so add them together
-2x-5y-2z=12
<u>-2x+5y+2z=4 +</u>
<u />-4x+0y+0z=16
-4x=16
divide both sides by 4
-x=4
multiply -1
x=-4
now we have
-4x-5y-z=18
-2x+5y+2z=4
add them together
-6x+0y+z=22
but x=-4 so
-6(-4)+z=22
24+z=22
subtract 24 from both sides
z =-2
subsitute into any equation
-2x-5y-2z=12
x=-4
z=-2
-2(-4)-5y-2(-2)=12
8-5y+4=12
12-5y=12
subtract 12 from both sides
-5y=0
y=0
x=-4
y=0
z=-2
There are 40 girls. The answer is 40.
Answer:
D is the answer on edg.
Step-by-step explanation:
