Step-by-step explanation:
thr standard form for a quadratic equation is:
ax²+bx+c
in this example, a=1, b=(-1), c=(-42)
Multiply 2x-5y= -21 by 3 to make it 6x-15y= -63
Multiply 3x-3y= -18 by -5 to make it -15x+15y=90
This cancels the y’s out which leaves us with
6x=-63
&
-15x=90
x for 6x=-63 equals - 10.5 so x is - 10.5 and for -15x=90, x= -6
Then you plug in x into any equation you’d like to find y.
Let’s plug in - 10.5 into 6x... equation.
6(- 10.5)-15y=-63
63-15y= -63
-63 -63
-15y=0
y=0 and x= - 10.5. When you plug in this values it makes the equation true!
But the correct answer is the first one north. Sorry if I’m doing too much hahah
If I’m confusing here’s the right answer...
6x-15y= -63
-15x+15y=90
You would take 7.5 and divide it by 2 which will give you C. 3.75
Answer:
Step-by-step explanation:
A cell has a radius: r = 3 nmThe surface area of a cell:A = 4 r² π = 4 · 3² π = 4 · 9 π = 36 π nm²The volume of a cell:V = 4/3 r³ π = 4/3 · 3³ π = 4 · 9 π = 36 π nm³Answer: The surface area is 36 π nm² and the volume is 36 π nm³.
