good morning guys teacher a here and welcome to Guru Pino sa America so for today on topic not I evaluating algebraic expressions sove expression numbers and letters so value so example number one so simpling given so example number one evaluate the given if x isal 10 so given x- 5 substitution method or plug inue X so x b given 10 so therefore xue which is 10 now after value X rest given which isus 5 and then isolve so 10 - 5 therefore the answer is five so next example number two so simp given evaluate the given if if Y is equal to4 number letter that means operation involved is multiplication so see YP so again is or Y which is-4 soop 3 and then palan yo y base a given -4 3 y means 3 * y so that means 3 * ne4 now 3 * -4 I -12 therefore answer number two I2 next so number three evaluate the given if x is equal to 5 and Y is equal to 3 wherein expression I 2x - 3 y y there so P again plug in X Y soop 2 and then palan X Bas of given it is five so 2x is 2 * 5 and then minus cop 3 my variable which is y palan y which is 3 so 3 y 3 * 3 now of operations where subtract so 2 * 5 I 10us 3 * 3 I 9 now given so 10 - 9 is = to 1 therefore the answer for number three is positive one or simply one next example number four okay so on given evaluate the expression if x is equal to 2 and Y is equal to -4 so expression I x^2 - 3x y + 2 y^ 2 again First Step ISS or plug Ines variables so x x i pos2 so two and then squared and then cus3 and then may variable which means number x i two and then followed by y Bas a given c y i -4 and then copy hand C + 2 and then y so y4 there so num following the pmas rule which means given expression exponent and thenes they are multiplication okay so 2 S 2 * 2 that will give us 4 and then 3 or -3 y minus sign n SO3 SO3 * 2 I -6 * -4 so -6 * -4 is positive 24 so mag + 24 okay and then pos2 plus 2 * -4 that will give us 8 so since plus and minus given that means from left to right so 4 + 24 I 28 and then Min - 8 therefore final answer I 20 so answer example positive 20 next example okay so last example eval the given if x is = to -1 Y is 3 and Z is equal to -2 where in expression I 12 parenthesis or time 2x^2 - 4 y + 5 Z again using substitution method letters ores rest n given so C2 and then parenthesis and then C2 and then x value x b given it's 1 so1 and thenare exponent parth and then cus4 so minus 4 and then y value is 3 so time 3 and then plus cop 5 Z Z2 so following the pendas rule my exponent syb and then two cop then -1 squ simplify -1 * 1 is pos1 and then separately so4 so -4 * 3 I -12 so as - 12 and then POS 5 * -2 I -1- 10 there now simplify 2 * 1 so 2 * 1 I 2 then gring symbol -2 - 10 so still following the P ruleth so therefore see 12 then parenthesis check 2 -2 I -10 - 10 so -10 - 10 I-20 so therefore final isve I 12 * 20 so by 1/2 * -20 that will give us10 so therefore kindly give me a like para share to YouTube sa so that's it for today guys see you on my next video Palam