All categories

1 year ago

If 2x – 10y = -1 and 5x + 6y = 4 are true equations, what would be the value of 7x - 4y?

Mathematics

1 answer:

Zigmanuir [339]1 year ago

8 0

Answer:

Step-by-step explanation:

If the equations are true, they can be solved simultaneously.

Consider 2x-10y=-1 as Eq1 and 5x+6y=4 as Eq2

Multiplying Eq1 with 3 and Eq2 with 5 we get,

6x-30y=-3 -- Eq3 and 25x+30y=20 -- Eq4

Adding Eq3 and Eq4,

31x=17 Therefore, x=17/31

Plugin x=17/31 in Eq3,

6(17/31)-30y=-3 --- y=13/62

Plug In values of x and y in 7x-4y we get,

7(17/31)-4(13/62) = 3

So the value of 7x-4y = 3.

You might be interested in

How many miles is it from Honolulu to pearl harbor

Semmy [17]

Answer:

9.1 miles

Step-by-step explanation:

3 0

3 years ago

H(t)=-10t+6<br> H(_____)=-44<br> Help me please.

alexira [117]

Answer:

-10t +6=-44

-10t=-44-6

-10t=-50

-50\-10

8 0

2 years ago

I really need help with this( 25 points to whoever answers)

masya89 [10]

Look over all of the possible answers. If any of them contains either M or N or both, the result is irrational. There's one exception: N^2 produces a rational number because the radical disappears.

6 0

2 years ago

Find the input (x) of the function y = -4/3x+ 20 if the output<br> (y) is -80

RideAnS [48]

Answer:

x=75

Step-by-step explanation:

4 0

3 years ago

Assume a researcher recruits 150 African American and Caucasian individuals taking warfarin to determine if there is a differenc

Anettt [7]

Answer:

Z=11.0

Step-by-step explanation:

Let Caucasian individuals be the population 1 and African American be the population 2. So, we are given that

n=150

n1=75

mean1=xbar1=6.1.

standard deviation1=S.D1=σ1=1.1.

Variance1=V(x1)=σ1²=1.1²=1.21.

n2=75.

mean2=xbar2=4.3.

standard deviation2=S.D2=σ2=0.9.

Variance2=V(x2)=σ2²=0.9²=0.81.

The z-statistic is

$Z=\frac{xbar1-xbar2}{\sqrt{\frac{V(x1)}{n1}+ \frac{V(x2)}{n2} } }$

$Z=\frac{6.1-4.3}{\sqrt{\frac{1.21}{75}+ \frac{0.81}{75} } }$

$Z=\frac{1.8}{\sqrt{0.0161+ 0.0108 } }$

$Z=\frac{1.8}{\sqrt{0.0269 } }$

$Z=\frac{1.8}{0.164 } }$

Z=10.97

Z=11.0

So, the z value obtained while calculating the test statistic is approximately 11.0.

4 0

2 years ago