a/c = d/a
you would cross multiply to get aa = cd
aa = a^2
so you would have a^2 = cd
The answer for angle b is: 25°
The system of the equation doesn't give the solution at (-3, -6).
<h2>Given to us</h2>
<h3>Equation 1,</h3>
-4x+y = 6
solve for y

<h3>Equation 2,</h3>
5x-y =21
substitute the value of y in equation 2,

Substitute the value of x in equation 2,

We can see that the solution of the two equations is at (27, 114). Also, it can be verified by plotting the line on the graph.
Hence, the system of the equation doesn't give the solution at (-3, -6).
Learn more about system of equations:
brainly.com/question/12895249
Answer:
3.33×10⁴
Step-by-step explanation:
You can use the hint, or you can use a common exponent. Here is the latter case.
(3.9×10⁴) -(5.7×10³) = (3.9×10⁴) -(0.57×10⁴) = (3.9 -0.57)×10⁴
= 3.33×10⁴
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With a little practice, you can see the effect on exponents of moving the decimal point. Here, we have ...
5.7×10³ = (0.57×10)×10³ = 0.57×(10×10³) = 0.57×10⁴
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When adding or subtracting in scientific notation, all that is required is that the exponents of all the numbers be the same. The hint says make all the exponents be 0. Above, we have chosen to make them all be 4. You could also use 3:
(3.9×10⁴) -(5.7×10³) = (39×10³) -(5.7×10³) = (39 -5.7)×10³
= 33.3×10³ = 3.33×10⁴