HELP AGAIN AGAIN AGAIN AGAIN FOR BRAINLIEST AND points

COMMON CORE REVIEW

masha68 [24]

Answer:

146.9

Step-by-step explanation:

I'm not sure of the answer but if I'm wrong tell me I'll continue trying it is a pleasure to help you.

7 0

2 years ago

Kalsom answers 25 questions in math tests. He scored 81% to 93%. Calculate all possible number of questions successfully answere

cricket20 [7]

Answer:

21 and 22

Step-by-step explanation:

Let's work backward from that 81%: x/25 = 0.81 yields x = 20.25. Nominally, 20.25 / 25 = 0.81, but x must be an integer. Let's round 20.25 off to 20.

Thus, if Kalsom got 81%, it was a result of his having done 20 questions correctly.

81% corresponds to 20 questions correct;

82% to 20.5 questions correct, or, rounding up, to 21 questions correct;

83% to 20.75, or 21;

84% to 21 questions correct; this is the only result that makes sense (whole number of questions answered correctly)

85% to 21.25;

86% to 21.5;

87% to 21.75;

88% to 22 questions correct (this makes sense, unlike the last three)

89% to 22.25;

90% to 22.5;

91% to 22.75;

Assuming that the number of questions correct MUST be integer, then the possible number correct are 21 and 22, corresponding to 84% and 88% respectively.

4 0

3 years ago

Dina and Masha started out on a 10 km bike path at the same time. When Dina reached the end of the 10 km, Masha still had 2 km l

labwork [276]

4 km/h because 10-2 because of the 2 km left which =8 then you divide that by 2 to figure out the km per hour which = 4 so 4 km/h

6 0

2 years ago

Read 2 more answers

Log(x-2)+log2=2logy<br>log(x-3y+3)=0

In-s [12.5K]

Answer:

Step-by-step explanation:

$\left\{\begin{array}{ccc}\log(x-2)+\log2=2\log y&(1)\\\log(x-3y+3)=0&(2)\end{array}\right$

$===========================\\\text{DOMAIN:}\\\\x-2>0\to x>2\\y>0\\x-3y+3>0\to x-3y>-3\\=====================\\\\\text{We know:}\ \log_ab=c\iff a^c=b,\\\\\text{therefore}\ \log_ab=0\iff a^0=b\to b=1\\\\\text{From this we have}\\\\\log(x-3y+3)=0\iff x-3y+3=1\qquad\text{add}\ 3y\ \text{to both sides}\\\\x+3=3y+1\qquad\text{subtract 3 from both isdes}\\\\\boxed{x=3y-2}\qquad(*)\\\\\text{Substitute it to (1)}$

$\log(3y-2-2)+\log2=2\log(y)\qquad\text{use}\ \log_ab^n=n\log_ab\\\\\log(3y-4)+\log2=\log(y^2)\qquad\text{subtract}\ \log(y^2)\ \text{from both sides}\\\\\log(3y-4)+\log2-\log(y^2)=0\\\\\text{Use}\ \log_ab+\log_ac=\log_a(bc)\ \text{and}\ \log_ab-\log_ac=\log_a\dfrac{b}{c}\\\\\log\dfrac{(3y-4)(2)}{y^2}=0\qquad\text{use}\ \log_ab=0\Rightarrow b=1\\\\\dfrac{(3y-4)(2)}{y^2}=1\iff y^2=(3y-4)(2)\\\\\text{Use the distributive property}\ a(b+c)=ab+ac$

$y^2=(3y)(2)+(-4)(2)\\\\y^2=6y-8\qquad\text{subtract}\ 6y\ \text{from both sides}\\\\y^2-6y=-8\qquad\text{add 8 to both sides}\\\\y^2-6y+8=0\\\\y^2-2y-4y+8=0\\\\y(y-2)-4(y-2)=0\\\\(y-2)(y-4)=0\iff y-2=0\ \vee\ y-4=0\\\\\boxed{y=2\ \vee\ y=4}\in D$

$\text{Put the values of}\ y\ \text{to }\ (*):\\\\\text{for}\ y=2:\\\\x=3(2)-2\\\\x=6-2\\\\\boxed{x=4}\in D\\\\\text{for}\ y=4:\\\\x=3(4)-2\\\\x=12-2\\\\\boxed{x=10}\in D$

4 0

2 years ago

Simplify the following by removing the brackets: a (b-c)+d (b-c)<br>

netineya [11]

Answer:

ab - ac + db - dc

Step-by-step explanation:

you distribute the variables inside the parenthesis

4 0

2 years ago