Question

15 multiple choice 2 points what is 47,000,000 in scientific notation? 0.47×10^7 47×10^6 4.7×10^6 4.7×10^7 16 multiple choice 2 points the value of y in the equation 0.06y + 200 = 0.03y + 350 is 5,000 18,333.3 500 1,666.6 17 multiple choice 2 points what is the value of x in the equation 2(x - 4) = 4(2x + 1)? -2 1/2 -1/2 2

Explanation:

Question 15

Step1: Recall scientific - notation form

Scientific notation is \(a\times10^{n}\), where \(1\leqslant a<10\) and \(n\) is an integer.

Step2: Convert 47000000 to scientific notation

Move the decimal point 7 places to the left to get \(a = 4.7\) and \(n=7\). So \(47000000=4.7\times 10^{7}\).

Step1: Rearrange the equation

Subtract \(0.03y\) from both sides: \(0.06y - 0.03y+200=0.03y - 0.03y + 350\), which simplifies to \(0.03y+200 = 350\).

Step2: Isolate the variable term

Subtract 200 from both sides: \(0.03y+200 - 200=350 - 200\), getting \(0.03y=150\).

Step3: Solve for \(y\)

Divide both sides by 0.03: \(y=\frac{150}{0.03}=5000\).

Step1: Expand both sides

Expand \(2(x - 4)\) to \(2x-8\) and \(4(2x + 1)\) to \(8x + 4\). So the equation becomes \(2x-8=8x + 4\).

Step2: Rearrange the terms

Subtract \(2x\) from both sides: \(2x-2x-8=8x-2x + 4\), getting \(-8 = 6x+4\).

Step3: Isolate the variable term

Subtract 4 from both sides: \(-8 - 4=6x+4 - 4\), which gives \(-12 = 6x\).

Step4: Solve for \(x\)

Divide both sides by 6: \(x=\frac{-12}{6}=-2\).

Answer:

D. \(4.7\times 10^{7}\)

Question 16