PEMDAS is a set of rules which are followed while solving mathematical expressions. These rules start with Parentheses, and then operations are performed on the exponents or powers. Next, we perform operations on multiplication or division from left to right. Finally, operations on addition or subtraction are performed from left to right.

8 0

2 years ago

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The coordinates of P and Q are (2,6) and (4,5) respectively. Equation of a line RS is Y= 2X -3. Determine if the lines are paral

Travka [436]

Answer:

Perpendicular

Step-by-step explanation:

Given points P=(2,6) and Q=(4,5)

The line RS is y=2x-3.

Now we know that the line joining any two points (x1,y1) and (x2,y2) has slope m= $\frac{y2-y1}{x2-x1}$

Now the slope of the line PQ is

m1= $\frac{5-6}{4-2}$ = - $\frac{1}{2}$

We know that the slope of the line in the form y=mx+c is m

So the line RS has slope m2=2

Now two lines are parallel if m1=m2

And those two lines are perpendicular if $m1*m2=-1$

here m1= - $\frac{1}{2}$ and m2=2

clearly $m1*m2=-1$

Therefore the two given lines are perpendicular

7 0

3 years ago

Dmitri wants to cover the top and sides of the box shown with glass tiles that are 5mm square. How many tiles does he need? ( Th

ycow [4]

Answer:

372

Step-by-step explanation:

We are given that the dimensions of the box are,

Length = 15 cm, Width = 20 cm and Height = 9 cm.

We know that the box represents a cuboid.

Since, surface area of a cuboid = L×W + 2×L×H + 2×W×H

Thus, the surface area of the box = 15×20 + 2×15×9 + 2×20×9

i.e. Surface area = 300 + 270 + 360

i.e. Surface area = 930.

Thus, the surface area of the box is 930 cm² i.e. 9300 mm².

Further, the sides of the tiles are 5 mm and the tile represents a square.

So, the surface area of the tile = 5 × 5 = 25 mm².

This gives us that,

Number of tiles required to cover the box = $\frac{9300}{25}$ = 372.

Hence, Dmitri requires 372 tiles to cover the box.

5 0

3 years ago

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Here's the question.

OleMash [197]

Answer:

The value of T₂₀ - T₁₅ is -20.

Step-by-step explanation:

Given :

>> If for an A.P, d = -4

To Find :

>> T₂₀ - T₁₅

Using Formula :

General term of an A.P.

$\star{\small{\underline{\boxed{\sf{\red{ T_n = a + (n - 1)d}}}}}}$

>> Tₙ = nᵗʰ term
>> a = first term
>> n = no. of terms
>> d = common difference

Solution :

Firstly finding the A.P of T₂₀ by substituting the values in the formula :

${\dashrightarrow{\pmb{\sf{ T_n = a + (n - 1)d}}}}$

${\dashrightarrow{\sf{ T_{20} = a + (20 - 1) d}}}$

${\dashrightarrow{\sf{ T_{20} = a + (19)d}}}$

${\dashrightarrow{\sf{ T_{20} = a + 19 \times d}}}$

${\dashrightarrow{\sf{ T_{20} = a + 19d}}}$

${\star \: {\underline{\boxed{\sf{\pink{ T_{20} = a + 19d}}}}}}$

Hence, the value of T₂₀ is a + 19d.

$\rule{190}1$

Secondly, finding the A.P of T₁₅ by substituting the values in the formula :

${\dashrightarrow{\pmb{\sf{ T_n = a + (n - 1)d}}}}$

${\dashrightarrow{\sf{ T_{15}= a + (15 - 1) d}}}$

${\dashrightarrow{\sf{ T_{15}= a + (14) d}}}$

${\dashrightarrow{\sf{ T_{15}= a + 14 \times d}}}$

${\dashrightarrow{\sf{ T_{15}= a + 14d}}}$

${\star{\underline{\boxed{\sf \pink{ T_{15}= a + 14d}}}}}$

Hence, the value of T₁₅ is a + 14d

$\rule{190}1$

Now, finding the difference between T₂₀ - T₁₅ :

${\dashrightarrow{\pmb{\sf{T_{20} - T_{15}}}}}$

${\dashrightarrow{\sf{(a + 19d) - (a + 14d)}}}$

${\dashrightarrow{\sf{a + 19d - a - 14d}}}$

${\dashrightarrow{\sf{a - a + 19d - 14d}}}$

${\dashrightarrow{\sf{0+ 19d - 14d}}}$

${\dashrightarrow{\sf{19d - 14d}}}$

${\dashrightarrow{\sf{5 \times - 4}}}$

${\dashrightarrow{\sf{ - 20}}}$

${\star \: \underline{\boxed{\sf{\pink{T_{20} - T_{15} = - 20}}}}}$

Hence, the value of T₂₀ - T₁₅ is -20.

$\underline{\rule{220pt}{3.5pt}}$

3 0

3 years ago