Sub in -7 for x to get 2(-7)+8 which is -14+8=-6. f(-7)= -6
Answer:Katie is 100 cm tall and is standing so that her mother's shado covers her shadow. She is 90 cm from her mother and her mother's shadow is 225cm long. How tall is her mother?
Step-by-step explanation:
Add 10 to both sides, so you get v=1


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<h3>I'm solving it using substitution method:-</h3>
<h3>7x+2y=3 {given}</h3>
<h3>=>7x=3-2y</h3>
<h3>=>x=(3-2y)/7-------(1)</h3>
<h3>x-3y=30 {given}</h3>
<h3>=>x=30+3y</h3>
<h3>=>(3-2y)/7=30+3y {putting the value of x from eqn 1}</h3>
<h3>=>3-2y=210+21y</h3>
<h3>=>3-210=21y+2y</h3>
<h3>=>-207=23y</h3>
<h3>=>y= -207/23= -9</h3>
<h3>putting the value of y on eqn(1):-</h3>
<h3>x=(3-2y)/7</h3>
<h3>x=>(3-2(-9))/7=(3+18)/7=21/7=3</h3>
<h2>Hence, x=3, y= -9</h2>
✌️✌️❤️❤️
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