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3 years ago

Evaluate −6a^3+8a^2+8a+1, when a=5.

Mathematics

1 answer:

EastWind [94]3 years ago

8 0

Answer:

-509

Step-by-step explanation:

1. Subsitute 5 for a in the expression. -6(5)^3+8(5)^2+8(5)+1

2. -6(125)+8(25)+40+1

3. -750+200+41

4. -509

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When y is 4, p is 0.5, and m is 2, x is 2. If x varies directly with the product of p and m and inversely with y, which equation

Radda [10]

<h3><u>Question:</u></h3>

When y is 4, p is 0.5, and m is 2, x is 2. If x varies directly with the product of p and m and inversely with y, which equation models the situation?

xpmy=8

xy/pm=8

xpm/y=0.5

x/pmy=0.5

<h3><u>Answer:</u></h3>

The equation models the situation is $\frac{x y}{p m}=8$

<h3><u>Solution:</u></h3>

Given that

x is 2, y is 4, p is 0.5, and m is 2

x varies directly with the product of p and m

x varies inversely with y

$\text {Product of } p \text { and } m=p \times m=p m$

x varies directly with the product of p and m

$=>x \propto p m$ ---- eqn 1

As x varies inversely with y,

$=>x \propto \frac{1}{y}$ ----- eqn 2

From (1) and 2, we can say that

$x \propto \frac{p m}{y}$

$\Rightarrow x=k \frac{p m}{y}$

where k is constant of proportionality

$\Rightarrow \frac{x y}{p m}=k$ ---- eqn 3

On substituting given values of x = 2, y = 4, p = 0.5 and m= 2 in eqn (3) we get

$\frac{x y}{p m}=\frac{2 \times 4}{0.5 \times 2}=k$

$\begin{array}{l}{\frac{x y}{p m}=\frac{8}{1}=k} \\\\ {=>\frac{x y}{p m}=8}\end{array}$

Hence correct option is second that is $\frac{x y}{p m}=8$

8 0

3 years ago

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Answer:

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Step-by-step explanation:

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