Question

hey plss help me solve


best one will be marked brainliest​

Answer 1

Step-by-step explanation:

x+y =4

+2x-5y=1

multiply equation 1 by 5

2x -5y = 1

+ 5x + 5y = 20

____________

7x = 21

x= 3

put in 1

x+y = 4

3 + y = 4

y = 4-3

y= 1

Answer 2

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1. PH Scale:-

The pH is a measure of the concentration of hydrogen ions, the acidity or alkalinity of a solution. The pH-scale is normally between 0 and 14. Aqueous solutions at 25 ° C with a pH of less than 7 are acidic and basic or alkaline solutions are those with a pH greater than 7.

2. Universal Indicator:-

A universal indicator is a pH indicator, composed of a solution of several compounds, that exhibits several smooth colour changes over a pH value range from 1-14 to indicate the acidity or alkalinity of solutions. For example, red cabbage juice.

Universal indicator is supplied as a solution or as universal indicator paper . It is a mixture of several different indicators. Unlike litmus, universal indicator can show us how strongly acidic or alkaline a solution is, not just that the solution is acidic or alkaline.