Question

Explanation of... Maria thinks of a number and subtracts 5/2 from it. She multiplies the result by 8. The result now obtained is 3 times the same number she thought of. What is the number??....... Plz explain as soon as possible.....​

Answer 1

Given :-

• Maria thinks of a number and subtracts 5/2 from it.
• She multiplies the result by 8.
• The result now obtained is 3 times the same number she thought of.

To Find :-

• What is the number.

Solution :-

Let,

$\mapsto \bf The\: number\: Maria\: thought =\: x$

Now,

$\bigstar$ She subtracts 5/2 from that number.

$\implies \sf Number - \dfrac{5}{2}$

$\implies \sf\bold{\purple{x - \dfrac{5}{2}}}$

Again,

$\bigstar$ She multiples the result by 8.

$\implies \sf 8 \times \bigg(x - \dfrac{5}{2}\bigg)$

$\implies \sf\bold{\purple{8\bigg(x - \dfrac{5}{2}\bigg)}}$

According to the question,

$\bigstar$ The result now obtained is 3 times the same number she thought of.

$\implies \sf 8\bigg(x - \dfrac{5}{2}\bigg) =\: 3 \times x$

$\implies \sf 8x - \dfrac{40}{2} =\: 3x$

$\implies \sf \dfrac{16x - 40}{2} =\: 3x$

By doing cross multiplication we get,

$\implies \sf 16x - 40 =\: 2(3x)$

$\implies \sf 16x - 40 =\: 6x$

$\implies \sf 16x - 6x =\: 40$

$\implies \sf 10x =\: 40$

$\implies \sf x =\: \dfrac{4\cancel{0}}{1\cancel{0}}$

$\implies \sf x =\: \dfrac{4}{1}$

$\implies \sf\bold{\red{x =\: 4}}$

${\small{\bold{\underline{\therefore\: The\: number\: that\: Maria\: thought\: is\: 4\: .}}}}$

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★ VERIFICATION ★

$\leadsto \sf 8\bigg(x - \dfrac{5}{2}\bigg) =\: 3x$

By putting x = 4 we get,

$\leadsto \sf 8\bigg(4 - \dfrac{5}{2}\bigg) =\: 3(4)$

$\leadsto \sf 32 - \dfrac{40}{2} =\: 3 \times 4$

$\leadsto \sf \dfrac{64 - 40}{2} =\: 12$

$\leadsto \sf \dfrac{\cancel{24}}{\cancel{2}} =\: 12$

$\leadsto \sf \dfrac{12}{1} =\: 12$

$\longrightarrow \bf 12 =\: 12$

Hence, Verified!

Answer 2

Answer:

it's a word problem of linear equations in one variable no?